md: simplify code with bio_io_error

Since bio_io_error sets bi_status to BLK_STS_IOERR,
and calls bio_endio, so we can use it directly.

And as mentioned by Shaohua, there are also two
places in raid5.c can use bio_io_error either.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 1d235cc..f50958d 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -790,8 +790,7 @@ static void flush_bio_list(struct r1conf *conf, struct bio *bio)
 		bio->bi_next = NULL;
 		bio->bi_bdev = rdev->bdev;
 		if (test_bit(Faulty, &rdev->flags)) {
-			bio->bi_status = BLK_STS_IOERR;
-			bio_endio(bio);
+			bio_io_error(bio);
 		} else if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
 				    !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
 			/* Just ignore it */