ceph: force updating the msg pointer in non-split case

stable inclusion
from stable-v5.10.181
commit 8c0109d76235543e8520b5e5ad9d71aa7368836e
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8GJZJ

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8c0109d76235543e8520b5e5ad9d71aa7368836e

--------------------------------

commit 4cafd040 upstream.

When the MClientSnap reqeust's op is not CEPH_SNAP_OP_SPLIT the
request may still contain a list of 'split_realms', and we need
to skip it anyway. Or it will be parsed as a corrupt snaptrace.

Cc: stable@vger.kernel.org
Link: https://tracker.ceph.com/issues/61200


Reported-by: Frank Schilder <frans@dtu.dk>
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>
(cherry picked from commit 8e701413)