bcache: use bio_set_dev to assign ->bi_bdev

Always use the bio_set_dev helper to assign ->bi_bdev to make sure
other state related to the device is uptodate.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/md/bcache/debug.c

@@ -114,7 +114,7 @@ void bch_data_verify(struct cached_dev *dc, struct bio *bio)
 	check = bio_kmalloc(GFP_NOIO, bio_segments(bio));
 	if (!check)
 		return;
-	check->bi_bdev = bio->bi_bdev;
+	bio_set_dev(check, bio->bi_bdev);
 	check->bi_opf = REQ_OP_READ;
 	check->bi_iter.bi_sector = bio->bi_iter.bi_sector;
 	check->bi_iter.bi_size = bio->bi_iter.bi_size;