cmake: Fix a typo in FindNSIS.
cmake: Fix a typo in FindNSIS.

clibs/cmocka,jschmidlapp/cmocka,jschmidlapp/cmocka,tyc/cmocka,jhrozek/cmocka,lsjostro/cmocka,jamesmunns/CMocka,tyc/cmocka,chadversary/cmocka,chadversary/cmocka,linuxmaniac/cmocka,wingyplus/cmocka,JonathonReinhart/cmocka,Odie/cmocka,VladimirTyrin/cmocka,dsch/cmocka,Odie/cmocka,nuumio/cmocka,JonathonReinhart/cmocka,aleksandr-vin/cmock,VladimirTyrin/cmocka,dsch/cmocka,jamesmunns/CMocka,nuumio/cmocka,wingyplus/cmocka,lsjostro/cmocka,clibs/cmocka,jschmidlapp/cmocka,tyc/cmocka,nuumio/cmocka,linuxmaniac/cmocka,jhrozek/cmocka,jhrozek/cmocka,aleksandr-vin/cmock,Odie/cmocka