configure: Remove unused brctl check
configure: Remove unused brctl check

brctl isn't used anywhere AFAICT

eskultety/libvirt,elmarco/libvirt,VenkatDatta/libvirt,crobinso/libvirt,jfehlig/libvirt,jfehlig/libvirt,agx/libvirt,nertpinx/libvirt,zippy2/libvirt,shugaoye/libvirt,agx/libvirt,agx/libvirt,zhlcindy/libvirt-1.1.4-maintain,datto/libvirt,shugaoye/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,datto/libvirt,fabianfreyer/libvirt,cbosdo/libvirt,andreabolognani/libvirt,nertpinx/libvirt,taget/libvirt,shugaoye/libvirt,jfehlig/libvirt,jardasgit/libvirt,libvirt/libvirt,zippy2/libvirt,fabianfreyer/libvirt,cbosdo/libvirt,taget/libvirt,crobinso/libvirt,rlaager/libvirt,rlaager/libvirt,zhlcindy/libvirt-1.1.4-maintain,olafhering/libvirt,agx/libvirt,crobinso/libvirt,libvirt/libvirt,rlaager/libvirt,jfehlig/libvirt,shugaoye/libvirt,taget/libvirt,cbosdo/libvirt,libvirt/libvirt,jardasgit/libvirt,datto/libvirt,elmarco/libvirt,shugaoye/libvirt,VenkatDatta/libvirt,olafhering/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,andreabolognani/libvirt,zhlcindy/libvirt-1.1.4-maintain,zhlcindy/libvirt-1.1.4-maintain,andreabolognani/libvirt,taget/libvirt,eskultety/libvirt,cbosdo/libvirt,olafhering/libvirt,jardasgit/libvirt,zhlcindy/libvirt-1.1.4-maintain,olafhering/libvirt,elmarco/libvirt,VenkatDatta/libvirt,datto/libvirt,nertpinx/libvirt,elmarco/libvirt,eskultety/libvirt,agx/libvirt,elmarco/libvirt,fabianfreyer/libvirt,rlaager/libvirt,fabianfreyer/libvirt,eskultety/libvirt,VenkatDatta/libvirt,datto/libvirt,taget/libvirt,eskultety/libvirt,zippy2/libvirt,zippy2/libvirt,libvirt/libvirt,jardasgit/libvirt,crobinso/libvirt,rlaager/libvirt,andreabolognani/libvirt,cbosdo/libvirt,jardasgit/libvirt,nertpinx/libvirt