virhook: do not save the return value of virBuildPath
virhook: do not save the return value of virBuildPath

This function returns -1 on allocation error, there's no
need to check the path for NULL again.

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