ceph: allow ceph_put_mds_session to take NULL or ERR_PTR

[ Upstream commit 7e65624d32b6e0429b1d3559e5585657f34f74a1 ]

...to simplify some error paths.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Luis Henriques <lhenriques@suse.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
4 files changed