dm snapshot: store pointer to target instance

Save pointer to dm_target in dm_snapshot structure.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-snap.h b/drivers/md/dm-snap.h
index 93bce5d..434d1db 100644
--- a/drivers/md/dm-snap.h
+++ b/drivers/md/dm-snap.h
@@ -132,7 +132,7 @@
 
 struct dm_snapshot {
 	struct rw_semaphore lock;
-	struct dm_table *table;
+	struct dm_target *ti;
 
 	struct dm_dev *origin;
 	struct dm_dev *cow;