util: virfile: Clarify setuid usage for virFileRemove
util: virfile: Clarify setuid usage for virFileRemove

Break these checks out into their own function, and clearly document
each one. This shouldn't change behavior

fabianfreyer/libvirt,datto/libvirt,datto/libvirt,fabianfreyer/libvirt,olafhering/libvirt,taget/libvirt,zippy2/libvirt,datto/libvirt,eskultety/libvirt,VenkatDatta/libvirt,taget/libvirt,jardasgit/libvirt,jfehlig/libvirt,andreabolognani/libvirt,libvirt/libvirt,crobinso/libvirt,zippy2/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,eskultety/libvirt,nertpinx/libvirt,jardasgit/libvirt,andreabolognani/libvirt,libvirt/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,crobinso/libvirt,crobinso/libvirt,datto/libvirt,taget/libvirt,libvirt/libvirt,olafhering/libvirt,nertpinx/libvirt,eskultety/libvirt,eskultety/libvirt,taget/libvirt,nertpinx/libvirt,eskultety/libvirt,olafhering/libvirt,nertpinx/libvirt,jfehlig/libvirt,datto/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,VenkatDatta/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,taget/libvirt,fabianfreyer/libvirt,olafhering/libvirt,andreabolognani/libvirt,crobinso/libvirt,zippy2/libvirt,fabianfreyer/libvirt,andreabolognani/libvirt,zippy2/libvirt,jfehlig/libvirt,andreabolognani/libvirt,libvirt/libvirt,jardasgit/libvirt