dm ebs: Fix incorrect checking for REQ_OP_FLUSH

REQ_OP_FLUSH was being treated as a flag, but the operation
part of bio->bi_opf must be treated as a whole. Change to
accessing the operation part via bio_op(bio) and checking
for equality.

Signed-off-by: John Dorminy <jdorminy@redhat.com>
Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
Fixes: d3c7b35 ("dm: add emulated block size target")
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Author: John Dorminy

drivers/md/dm-ebs-target.c

@@ -363,7 +363,7 @@ static int ebs_map(struct dm_target *ti, struct bio *bio)
 	bio_set_dev(bio, ec->dev->bdev);
 	bio->bi_iter.bi_sector = ec->start + dm_target_offset(ti, bio->bi_iter.bi_sector);
 
-	if (unlikely(bio->bi_opf & REQ_OP_FLUSH))
+	if (unlikely(bio_op(bio) == REQ_OP_FLUSH))
 		return DM_MAPIO_REMAPPED;
 	/*
 	 * Only queue for bufio processing in case of partial or overlapping buffers