nwfilter: Clean up a couple nwfilter_driver error paths
nwfilter: Clean up a couple nwfilter_driver error paths

No need to goto cleanup and check "if (obj)" if we know (obj) isn't there,
so just return immediately.

Signed-off-by: John Ferlan <87558058f6f829e5ec976c8ef960720af4ff9c7d@redhat.com>

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