dm: call blk_queue_split() to impose device limits on bios

Otherwise the incoming bios, of various types, won't be shaped based on
the DM device's advertised limits.

Depends-on: af67c31fba ("blk: remove bio_set arg from blk_queue_split()")
Fixes: 744889b7cb ("block: don't deal with discard limit in blkdev_issue_discard()")
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm.c

@@ -1593,6 +1593,8 @@ static blk_qc_t __split_and_process_bio(struct mapped_device *md,
 		return ret;
 	}
 
+	blk_queue_split(md->queue, &bio);
+
 	init_clone_info(&ci, md, map, bio);
 
 	if (bio->bi_opf & REQ_PREFLUSH) {