dm btree: remove unused "dm_block_t root" parameter in btree_split_sibling()

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c
index c7726ce..b6cec25 100644
--- a/drivers/md/persistent-data/dm-btree.c
+++ b/drivers/md/persistent-data/dm-btree.c
@@ -420,8 +420,8 @@
  *
  * Where A* is a shadow of A.
  */
-static int btree_split_sibling(struct shadow_spine *s, dm_block_t root,
-			       unsigned parent_index, uint64_t key)
+static int btree_split_sibling(struct shadow_spine *s, unsigned parent_index,
+			       uint64_t key)
 {
 	int r;
 	size_t size;
@@ -625,7 +625,7 @@
 			if (top)
 				r = btree_split_beneath(s, key);
 			else
-				r = btree_split_sibling(s, root, i, key);
+				r = btree_split_sibling(s, i, key);
 
 			if (r < 0)
 				return r;