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 
7083abbbf.
Fixes: 7083abbbf ("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>
        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);