ceph: cleanup traceless reply handling for rename

ceph_fill_trace() already calls ceph_invalidate_dir_request() for
traceless reply. No need to duplicate the code in ceph_rename().

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>