clamav: fix with-pcre for non-/usr/local installs.
clamav: fix with-pcre for non-/usr/local installs.

Closes #47683.

Signed-off-by: Mike McQuaid <a17fed27eaa842282862ff7c1b9c8395a26ac320@mikemcquaid.com>

brunchboy/homebrew,Homebrew/linuxbrew,haihappen/homebrew,treyharris/homebrew,liamstask/homebrew,influxdb/homebrew,dickeyxxx/homebrew,benjaminfrank/homebrew,Linuxbrew/linuxbrew,kenips/homebrew,SteveClement/homebrew,keith/homebrew,benjaminfrank/homebrew,dplarson/homebrew,Angeldude/linuxbrew,saketkc/linuxbrew,OJFord/homebrew,frodeaa/homebrew,ybott/homebrew,iandennismiller/homebrew,influxdata/homebrew,davydden/linuxbrew,johanhammar/homebrew,deorth/homebrew,decors/homebrew,apjanke/homebrew,decors/homebrew,iostat/homebrew2,MartinDelille/homebrew,3van/homebrew,dunn/homebrew,deorth/homebrew,cprecioso/homebrew,SuperNEMO-DBD/cadfaelbrew,reelsense/homebrew,slyphon/homebrew,MartinDelille/homebrew,BrewTestBot/homebrew,filcab/homebrew,recruit-tech/homebrew,sferik/homebrew,sometimesfood/homebrew,sakra/homebrew,mobileoverlord/homebrew-1,georgschoelly/homebrew,SuperNEMO-DBD/cadfaelbrew,royhodgman/homebrew,influxdata/homebrew,ralic/homebrew,getgauge/homebrew,getgauge/homebrew,dericed/homebrew,vigo/homebrew,retrography/homebrew,TaylorMonacelli/homebrew,tutumcloud/homebrew,treyharris/homebrew,menivaitsi/homebrew,esamson/homebrew,iandennismiller/homebrew,galaxy001/homebrew,mmizutani/homebrew,michaKFromParis/homebrew-sparks,miketheman/homebrew,afh/homebrew,cscetbon/homebrew,brunchboy/homebrew,Angeldude/linuxbrew,vigo/homebrew,mkrapp/homebrew,iostat/homebrew2,bukzor/linuxbrew,gnubila-france/linuxbrew,LinusU/homebrew,utzig/homebrew,cprecioso/homebrew,galaxy001/homebrew,base10/homebrew,dalanmiller/homebrew,SteveClement/homebrew,dplarson/homebrew,Chilledheart/homebrew,davydden/linuxbrew,OJFord/homebrew,elyscape/homebrew,afh/homebrew,ear/homebrew,recruit-tech/homebrew,dickeyxxx/homebrew,sjackman/linuxbrew,ybott/homebrew,MartinDelille/homebrew,thinker0/homebrew,jamer/homebrew,retrography/homebrew,hakamadare/homebrew,gicmo/homebrew,utzig/homebrew,esamson/homebrew,elyscape/homebrew,tschoonj/homebrew,mobileoverlord/homebrew-1,vigo/homebrew,ebouaziz/linuxbrew,saketkc/linuxbrew,ebouaziz/linuxbrew,TaylorMonacelli/homebrew,frodeaa/homebrew,Linuxbrew/linuxbrew,bigbes/homebrew,totalvoidness/homebrew,elyscape/homebrew,polishgeeks/homebrew,eighthave/homebrew,youtux/homebrew,josa42/homebrew,danieroux/homebrew,elyscape/homebrew,reelsense/linuxbrew,alebcay/homebrew,vigo/homebrew,pcottle/homebrew,kenips/homebrew,kodabb/homebrew,dgageot/homebrew,princeofdarkness76/homebrew,redpen-cc/homebrew,eighthave/homebrew,MoSal/homebrew,optikfluffel/homebrew,ybott/homebrew,yazuuchi/homebrew,dongcarl/homebrew,polishgeeks/homebrew,base10/homebrew,ryanfb/homebrew,influxdata/homebrew,alebcay/homebrew,Chilledheart/homebrew,tutumcloud/homebrew,kenips/homebrew,AlexejK/homebrew,SuperNEMO-DBD/cadfaelbrew,drbenmorgan/linuxbrew,arnested/homebrew,ilovezfs/homebrew,kevinastone/homebrew,haihappen/homebrew,Homebrew/linuxbrew,LinusU/homebrew,jarrettmeyer/homebrew,zchee/homebrew,TaylorMonacelli/homebrew,scorphus/homebrew,bigbes/homebrew,marcwebbie/homebrew,drbenmorgan/linuxbrew,dunn/homebrew,thinker0/homebrew,Red54/homebrew,mkrapp/homebrew,scorphus/homebrew,keith/homebrew,decors/homebrew,zchee/homebrew,ryanfb/homebrew,booi/homebrew,OJFord/homebrew,totalvoidness/homebrew,reelsense/linuxbrew,pcottle/homebrew,kevinastone/homebrew,josa42/homebrew,emcrisostomo/homebrew,skinny-framework/homebrew,youtux/homebrew,retrography/homebrew,base10/homebrew,knpwrs/homebrew,georgschoelly/homebrew,johanhammar/homebrew,scpeters/homebrew,MoSal/homebrew,ento/homebrew,DoomHammer/linuxbrew,ear/homebrew,knpwrs/homebrew,hakamadare/homebrew,osimola/homebrew,influxdb/homebrew,ablyler/homebrew,feelpp/homebrew,dgageot/homebrew,skinny-framework/homebrew,bukzor/linuxbrew,mactkg/homebrew,sometimesfood/homebrew,mactkg/homebrew,hanxue/homebrew,skinny-framework/homebrew,Red54/homebrew,jconley/homebrew,totalvoidness/homebrew,pdxdan/homebrew,benjaminfrank/homebrew,yumitsu/homebrew,kodabb/homebrew,dongcarl/homebrew,muellermartin/homebrew,muellermartin/homebrew,ento/homebrew,kevinastone/homebrew,utzig/homebrew,Linuxbrew/linuxbrew,theeternalsw0rd/homebrew,TaylorMonacelli/homebrew,dongcarl/homebrew,gicmo/homebrew,ablyler/homebrew,theeternalsw0rd/homebrew,osimola/homebrew,arnested/homebrew,slyphon/homebrew,ilovezfs/homebrew,youtux/homebrew,youtux/homebrew,recruit-tech/homebrew,drbenmorgan/linuxbrew,booi/homebrew,quantumsteve/homebrew,BrewTestBot/homebrew,drewwells/homebrew,dplarson/homebrew,nandub/homebrew,recruit-tech/homebrew,hanxue/homebrew,gicmo/homebrew,tutumcloud/homebrew,haihappen/homebrew,drbenmorgan/linuxbrew,zchee/homebrew,afh/homebrew,optikfluffel/homebrew,eighthave/homebrew,ryanfb/homebrew,skatsuta/homebrew,pdxdan/homebrew,ablyler/homebrew,knpwrs/homebrew,quantumsteve/homebrew,elgertam/homebrew,thinker0/homebrew,lrascao/homebrew,emcrisostomo/homebrew,dericed/homebrew,joshfriend/homebrew,gnubila-france/linuxbrew,base10/homebrew,galaxy001/homebrew,Homebrew/homebrew,DoomHammer/linuxbrew,ear/homebrew,dunn/homebrew,mobileoverlord/homebrew-1,MartinDelille/homebrew,skatsuta/homebrew,sferik/homebrew,Homebrew/linuxbrew,Asuranceturix/homebrew,elgertam/homebrew,3van/homebrew,cscetbon/homebrew,jamer/homebrew,jarrettmeyer/homebrew,mmizutani/homebrew,pcottle/homebrew,ear/homebrew,Homebrew/homebrew,skatsuta/homebrew,mkrapp/homebrew,Homebrew/linuxbrew,osimola/homebrew,michaKFromParis/homebrew-sparks,kodabb/homebrew,ralic/homebrew,feelpp/homebrew,AlexejK/homebrew,alebcay/homebrew,3van/homebrew,lrascao/homebrew,reelsense/homebrew,MoSal/homebrew,mobileoverlord/homebrew-1,hanxue/homebrew,ExtremeMan/homebrew,LinusU/homebrew,yazuuchi/homebrew,lrascao/homebrew,MoSal/homebrew,bukzor/linuxbrew,hongkongkiwi/homebrew,redpen-cc/homebrew,sometimesfood/homebrew,drewwells/homebrew,Asuranceturix/homebrew,skinny-framework/homebrew,scorphus/homebrew,muellermartin/homebrew,knpwrs/homebrew,josa42/homebrew,marcwebbie/homebrew,miketheman/homebrew,gawbul/homebrew,drewwells/homebrew,royhodgman/homebrew,influxdb/homebrew,3van/homebrew,kodabb/homebrew,ExtremeMan/homebrew,ento/homebrew,jconley/homebrew,teslamint/homebrew,booi/homebrew,cprecioso/homebrew,royhodgman/homebrew,mactkg/homebrew,jsjohnst/homebrew,yumitsu/homebrew,cosmo0920/homebrew,kenips/homebrew,teslamint/homebrew,feelpp/homebrew,iandennismiller/homebrew,arnested/homebrew,apjanke/homebrew,slyphon/homebrew,Linuxbrew/linuxbrew,Homebrew/homebrew,getgauge/homebrew,ralic/homebrew,cprecioso/homebrew,pcottle/homebrew,elgertam/homebrew,sometimesfood/homebrew,liamstask/homebrew,emcrisostomo/homebrew,joshfriend/homebrew,dickeyxxx/homebrew,BrewTestBot/homebrew,danieroux/homebrew,jamer/homebrew,bigbes/homebrew,influxdb/homebrew,menivaitsi/homebrew,BrewTestBot/homebrew,LinusU/homebrew,tutumcloud/homebrew,galaxy001/homebrew,yumitsu/homebrew,dalanmiller/homebrew,jamer/homebrew,Angeldude/linuxbrew,ralic/homebrew,johanhammar/homebrew,ilovezfs/homebrew,ento/homebrew,Chilledheart/homebrew,iandennismiller/homebrew,kevinastone/homebrew,cosmo0920/homebrew,polishgeeks/homebrew,princeofdarkness76/homebrew,ebouaziz/linuxbrew,joshfriend/homebrew,sakra/homebrew,quantumsteve/homebrew,decors/homebrew,Asuranceturix/homebrew,scpeters/homebrew,deorth/homebrew,emcrisostomo/homebrew,princeofdarkness76/homebrew,reelsense/linuxbrew,filcab/homebrew,utzig/homebrew,influxdata/homebrew,brunchboy/homebrew,DoomHammer/linuxbrew,jconley/homebrew,apjanke/homebrew,Red54/homebrew,scpeters/homebrew,georgschoelly/homebrew,georgschoelly/homebrew,bigbes/homebrew,dutchcoders/homebrew,davydden/linuxbrew,hongkongkiwi/homebrew,muellermartin/homebrew,theeternalsw0rd/homebrew,eighthave/homebrew,cosmo0920/homebrew,sjackman/linuxbrew,teslamint/homebrew,ablyler/homebrew,Red54/homebrew,sjackman/linuxbrew,treyharris/homebrew,cscetbon/homebrew,adamliter/homebrew,ryanfb/homebrew,Angeldude/linuxbrew,gawbul/homebrew,drewwells/homebrew,reelsense/homebrew,gnubila-france/linuxbrew,thinker0/homebrew,princeofdarkness76/homebrew,cosmo0920/homebrew,reelsense/homebrew,SteveClement/homebrew,haihappen/homebrew,mmizutani/homebrew,dalanmiller/homebrew,AlexejK/homebrew,SteveClement/homebrew,scorphus/homebrew,frodeaa/homebrew,yazuuchi/homebrew,quantumsteve/homebrew,slyphon/homebrew,nandub/homebrew,miketheman/homebrew,Chilledheart/homebrew,keith/homebrew,gnubila-france/linuxbrew,frodeaa/homebrew,nandub/homebrew,menivaitsi/homebrew,filcab/homebrew,jsjohnst/homebrew,dongcarl/homebrew,tschoonj/homebrew,gawbul/homebrew,theeternalsw0rd/homebrew,dgageot/homebrew,apjanke/homebrew,royhodgman/homebrew,davydden/linuxbrew,hakamadare/homebrew,dericed/homebrew,mactkg/homebrew,feelpp/homebrew,adamliter/homebrew,hanxue/homebrew,liamstask/homebrew,dutchcoders/homebrew,marcwebbie/homebrew,redpen-cc/homebrew,jarrettmeyer/homebrew,reelsense/linuxbrew,benjaminfrank/homebrew,alebcay/homebrew,yazuuchi/homebrew,tschoonj/homebrew,iostat/homebrew2,polishgeeks/homebrew,dalanmiller/homebrew,pcottle/homebrew,dgageot/homebrew,danieroux/homebrew,ilovezfs/homebrew,sferik/homebrew,retrography/homebrew,chadcatlett/homebrew,optikfluffel/homebrew,totalvoidness/homebrew,jsjohnst/homebrew,tschoonj/homebrew,iostat/homebrew2,dplarson/homebrew,hakamadare/homebrew,dutchcoders/homebrew,skatsuta/homebrew,Asuranceturix/homebrew,sjackman/linuxbrew,SuperNEMO-DBD/cadfaelbrew,adamliter/homebrew,jarrettmeyer/homebrew,esamson/homebrew,ebouaziz/linuxbrew,optikfluffel/homebrew,esamson/homebrew,chadcatlett/homebrew,bukzor/linuxbrew,elgertam/homebrew,dunn/homebrew,zchee/homebrew,DoomHammer/linuxbrew,johanhammar/homebrew,OJFord/homebrew,arnested/homebrew,brunchboy/homebrew,ybott/homebrew,jsjohnst/homebrew,AlexejK/homebrew,Homebrew/homebrew,miketheman/homebrew,dutchcoders/homebrew,pdxdan/homebrew,sakra/homebrew,ExtremeMan/homebrew,nandub/homebrew,getgauge/homebrew,liamstask/homebrew,gicmo/homebrew,dickeyxxx/homebrew,michaKFromParis/homebrew-sparks,SteveClement/homebrew,saketkc/linuxbrew,keith/homebrew,danieroux/homebrew,chadcatlett/homebrew,redpen-cc/homebrew,saketkc/linuxbrew,dericed/homebrew,teslamint/homebrew,marcwebbie/homebrew,filcab/homebrew,sakra/homebrew,afh/homebrew,mmizutani/homebrew,treyharris/homebrew,hongkongkiwi/homebrew,osimola/homebrew,ExtremeMan/homebrew,sferik/homebrew,adamliter/homebrew,hongkongkiwi/homebrew,Asuranceturix/homebrew,menivaitsi/homebrew,jconley/homebrew,scpeters/homebrew,pdxdan/homebrew