dm mpath: remove annoying message of 'blk_get_request() returned -11'

It is very normal to see allocation failure, especially with blk-mq
request_queues, so it's unnecessary to report this error and annoy
people.

In practice this 'blk_get_request() returned -11' error gets logged
quite frequently when a blk-mq DM multipath device sees heavy IO.

This change is marked for stable@ because the annoying message in
question was included in stable@ commit 7083abbb.

Fixes: 7083abbb ("dm mpath: avoid that path removal can trigger an infinite loop")
Cc: stable@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm-mpath.c

@@ -499,8 +499,6 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
 	if (IS_ERR(clone)) {
 		/* EBUSY, ENODEV or EWOULDBLOCK: requeue */
 		bool queue_dying = blk_queue_dying(q);
-		DMERR_LIMIT("blk_get_request() returned %ld%s - requeuing",
-			    PTR_ERR(clone), queue_dying ? " (path offline)" : "");
 		if (queue_dying) {
 			atomic_inc(&m->pg_init_in_progress);
 			activate_or_offline_path(pgpath);