filestore: lfn_unlink removes the entry as last step
filestore: lfn_unlink removes the entry as last step

so that if it crashes in the middle of operation we're not left
with a hole in the list of objects. In case of a crash, recovery
should fix any stale objects. Also it is currently assumed that
we're currently the only users and there are no concurrent
operations.

ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph