block: switch bios to blk_status_t

Replace bi_error with a new bi_status to allow for a clear conversion.
Note that device mapper overloaded bi_error with a private value, which
we'll have to keep arround at least for now and thus propagate to a
proper blk_status_t value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/drivers/md/dm-bio-prison-v1.c b/drivers/md/dm-bio-prison-v1.c
index ae7da2c..82d2738 100644
--- a/drivers/md/dm-bio-prison-v1.c
+++ b/drivers/md/dm-bio-prison-v1.c
@@ -229,7 +229,7 @@ void dm_cell_release_no_holder(struct dm_bio_prison *prison,
 EXPORT_SYMBOL_GPL(dm_cell_release_no_holder);
 
 void dm_cell_error(struct dm_bio_prison *prison,
-		   struct dm_bio_prison_cell *cell, int error)
+		   struct dm_bio_prison_cell *cell, blk_status_t error)
 {
 	struct bio_list bios;
 	struct bio *bio;
@@ -238,7 +238,7 @@ void dm_cell_error(struct dm_bio_prison *prison,
 	dm_cell_release(prison, cell, &bios);
 
 	while ((bio = bio_list_pop(&bios))) {
-		bio->bi_error = error;
+		bio->bi_status = error;
 		bio_endio(bio);
 	}
 }