dm: rename target's per_bio_data_size to per_io_data_size

Request-based DM will also make use of per_bio_data_size.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index f2a363a..b3ccf1e 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -1121,7 +1121,7 @@
 
 	ti->num_flush_bios = 1;
 	ti->num_discard_bios = 1;
-	ti->per_bio_data_size = sizeof(struct dm_raid1_bio_record);
+	ti->per_io_data_size = sizeof(struct dm_raid1_bio_record);
 	ti->discard_zeroes_data_unsupported = true;
 
 	ms->kmirrord_wq = alloc_workqueue("kmirrord", WQ_MEM_RECLAIM, 0);