mds: clean out rename subtree cruft
mds: clean out rename subtree cruft

We used to force these subtrees for rename.  We don't anymore.. this is
old weirdness.

Signed-off-by: Sage Weil <6dd34506bbd5e58221bbb3e4732d97c91f02277b@newdream.net>

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