ceph: handle errors during osd client init

Unwind initializing if we get ENOMEM during client initialization.

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

diff --cc fs/ceph/mds_client.c
Simple merge

diff --cc fs/ceph/mds_client.h
Simple merge

diff --cc fs/ceph/osd_client.c
Simple merge

diff --cc fs/ceph/super.c
Simple merge