md/md-linear: enable io accounting

use md_account_bio() to enable io accounting, also make sure
mddev_suspend() will wait for all io to be done.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230621165110.1498313-8-yukuai1@huaweicloud.com

drivers/md/md-linear.c

@@ -238,6 +238,7 @@ static bool linear_make_request(struct mddev *mddev, struct bio *bio)
 		bio = split;
 	}
 
+	md_account_bio(mddev, &bio);
 	bio_set_dev(bio, tmp_dev->rdev->bdev);
 	bio->bi_iter.bi_sector = bio->bi_iter.bi_sector -
 		start_sector + data_offset;