docs: fix description of `docker swarm update --help`
docs: fix description of `docker swarm update --help`

Signed-off-by: Kei Ohmura <82a3f76f5859104098e1c763aea3695df488375c@gmail.com>

haveatry/docker,dccurtis/docker,jwhonce/docker,konstruktoid/docker-upstream,lixiaobing10051267/docker,jameszhan/docker,rancher/docker,sdurrheimer/docker,erikh/docker,dgageot/docker,cyphar/docker,amatsus/docker,trebonian/docker,moby/moby,Mokolea/docker,yasiramin10p/moby,flavio/docker,lixiaobing1/docker,tophj-ibm/moby,maxamillion/docker,tophj-ibm/docker,thtanaka/docker,moby/moby,madhanrm/docker,erikstmartin/docker,ffoysal/docker,hqhq/moby,ffoysal/docker,mtesselH/docker,sterchelen/docker,ffoysal/docker,sarnautov/moby,diogomonica/docker,erikstmartin/docker,dsheets/moby,scotttlin/docker,rancher/docker,jvanz/docker,naveed-jamil-tenpearls/moby,danyalKhaliq10p/moby,tonistiigi/docker,YuPengZTE/docker,michael-holzheu/docker,madhanrm/docker,ibuildthecloud/docker,madhanrm/docker,shhsu/docker,bonczj/moby-json-file-logger,coolljt0725/docker,harche/docker,sterchelen/docker,AkihiroSuda/docker,diogomonica/docker,gjaskiewicz/moby,vdemeester/docker,charleszheng44/moby,coolljt0725/docker,laijs/docker,yasiramin10p/moby,trebonian/docker,nawawi/docker,nawawi/docker,KarthikNayak/docker,kencochrane/docker,allencloud/docker,ibuildthecloud/docker,whuwxl/docker,gjaskiewicz/moby,cyphar/docker,qudongfang/docker,tonistiigi/docker,justincormack/docker,xuxinkun/docker,tophj-ibm/moby,michael-holzheu/docker,Mokolea/docker,dims/docker,thaJeztah/docker,moypray/docker,ColinHebert/docker,nawawi/docker,jimjag/docker,docker/docker,konstruktoid/docker-upstream,sarnautov/moby,duglin/docker,pramodhkp/moby,srust/docker,flavio/docker,flavio/docker,rremer/moby,q384566678/docker,nalind/docker,duglin/docker,akira-baruah/docker,cpuguy83/docker,mikebrow/docker,raja-sami-10p/moby,kencochrane/docker,yongtang/docker,qudongfang/docker,dmcgowan/docker,HideoYamauchi/docker,estesp/docker,mtesselH/docker,konstruktoid/docker-upstream,gschaetz/moby,gschaetz/moby,dmcgowan/docker,harche/docker,POLJM242/docker,paralin/docker,moby/moby,YuPengZTE/docker,bonczj/moby-json-file-logger,prertik/docker,erikh/docker,shhsu/docker,unclejack/docker,KarthikNayak/docker,sterchelen/docker,alfred-landrum/docker,dccurtis/docker,noironetworks/docker,haveatry/docker,bearstech/moby,bearstech/moby,kolyshkin/docker,dims/docker,x1022as/docker,djs55/docker,lixiaobing1/docker,resin-io/docker,mikedougherty/docker,konstruktoid/docker-1,yummypeng/docker,ndeloof/docker,liaoqingwei/docker,kolyshkin/moby,AkihiroSuda/docker,ColinHebert/docker,jvanz/docker,gnailuy/docker,dgageot/docker,mstanleyjones/docker,miminar/docker,mkumatag/docker,mikebrow/docker,liaoqingwei/docker,mike1729/docker,SvenDowideit/docker,KingEmet/docker,cpuguy83/docker,amatsus/docker,mahak/docker,moypray/docker,gnailuy/docker,tophj-ibm/docker,yummypeng/docker,jwhonce/docker,crosbymichael/docker,rhatdan/docker,rremer/moby,kojiromike/docker,charleszheng44/moby,ColinHebert/docker,Ramzec/docker,danyalKhaliq10p/moby,miminar/docker,lixiaobing10051267/docker,allencloud/docker,KingEmet/docker,x1022as/docker,PatrickLang/moby,crosbymichael/docker,yosifkit/docker,shishir-a412ed/docker,qudongfang/docker,estesp/docker,whuwxl/docker,ibuildthecloud/docker,tianon/docker,yummypeng/docker,noironetworks/docker,dsheets/moby,amatsus/docker,laijs/docker,laijs/docker,nalind/docker,shishir-a412ed/docker,tmp6154/docker,mahak/docker,thtanaka/docker,maxamillion/docker,tklauser/docker,mstanleyjones/docker,konstruktoid/docker-1,Ramzec/docker,thaJeztah/docker,jwhonce/docker,thtanaka/docker,tophj-ibm/moby,flavio/docker,bonczj/moby-json-file-logger,yosifkit/docker,xuxinkun/docker,tklauser/docker,mahak/docker,justincormack/docker,scotttlin/docker,lixiaobing1/docker,estesp/docker,liaoqingwei/docker,mixja/docker,catinthesky/docker,mike1729/docker,yosifkit/docker,docker/docker,jthelin/docker,q384566678/docker,tmp6154/docker,akira-baruah/docker,tklauser/docker,konstruktoid/docker-upstream,jvanz/docker,gnailuy/docker,moul/docker,moul/docker,duglin/docker,q384566678/docker,gjaskiewicz/moby,xuxinkun/docker,diogomonica/docker,djs55/docker,haveatry/docker,djs55/docker,mstanleyjones/docker,nalind/docker,sdurrheimer/docker,ripcurld0/moby,maxamillion/docker,noironetworks/docker,thaJeztah/docker,mikedougherty/docker,sdurrheimer/docker,tonistiigi/docker,naveed-jamil-tenpearls/moby,Mokolea/docker,kojiromike/docker,HideoYamauchi/docker,rhatdan/docker,jlhawn/docker,whuwxl/docker,alfred-landrum/docker,crosbymichael/docker,konstruktoid/docker-1,mixja/docker,laijs/moby,Ramzec/docker,tmp6154/docker,johnstep/moby-moby,dims/docker,coolljt0725/docker,dperny/docker,dmcgowan/docker,docker/docker,trebonian/docker,ndeloof/docker,bearstech/moby,jthelin/docker,Ramzec/docker,dperny/docker,yosifkit/docker,shhsu/docker,ibuildthecloud/docker,coreos/docker,mtesselH/docker,moby/moby,unclejack/docker,ibuildthecloud/docker,resin-io/docker,cyphar/docker,paralin/docker,catinthesky/docker,erikh/docker,PatrickLang/moby,srust/docker,miminar/docker,AkihiroSuda/docker,pradipd/moby,michael-holzheu/docker,mikedougherty/docker,moul/docker,rremer/moby,cpuguy83/docker,tophj-ibm/docker,rancher/docker,sarnautov/moby,darrenstahlmsft/moby,x1022as/docker,laijs/moby,pramodhkp/moby,gnailuy/docker,dgageot/docker,HideoYamauchi/docker,mixja/docker,nawawi/docker,prertik/docker,YuPengZTE/docker,fcrisciani/docker,jimjag/docker,charleszheng44/moby,Syntaxide/docker,kencochrane/docker,unclejack/docker,mahak/docker,jlhawn/docker,srust/docker,hqhq/moby,prertik/docker,Mokolea/docker,darrenstahlmsft/docker,Syntaxide/docker,kolyshkin/moby,KingEmet/docker,johnstep/moby-moby,imkin/moby,SvenDowideit/docker,dccurtis/docker,POLJM242/docker,kolyshkin/docker,naveed-jamil-tenpearls/moby,moypray/docker,cpuguy83/docker,darrenstahlmsft/docker,coreos/docker,scotttlin/docker,darrenstahlmsft/moby,Syntaxide/docker,mike1729/docker,pramodhkp/moby,darrenstahlmsft/docker,catinthesky/docker,jameszhan/docker,pradipd/moby,JMesser81/docker,jimjag/docker,ripcurld0/moby,kolyshkin/moby,mkumatag/docker,darrenstahlmsft/moby,coreos/docker,mikebrow/docker,johnstep/moby-moby,imkin/moby,AkihiroSuda/docker,dsheets/moby,jlhawn/docker,PatrickLang/moby,yongtang/docker,shishir-a412ed/docker,raja-sami-10p/moby,imkin/moby,ndeloof/docker,yongtang/docker,thaJeztah/docker,laijs/moby,moul/docker,raja-sami-10p/moby,paralin/docker,dperny/docker,lixiaobing10051267/docker,tianon/docker,yasiramin10p/moby,trebonian/docker,fcrisciani/docker,vdemeester/docker,mkumatag/docker,paralin/docker,fcrisciani/docker,pradipd/moby,SvenDowideit/docker,JMesser81/docker,allencloud/docker,justincormack/docker,vdemeester/docker,danyalKhaliq10p/moby,kojiromike/docker,jameszhan/docker,gschaetz/moby,hqhq/moby,ripcurld0/moby,bearstech/moby,rhatdan/docker,erikstmartin/docker,alfred-landrum/docker,JMesser81/docker,KarthikNayak/docker,harche/docker,nalind/docker,resin-io/docker,jimjag/docker