btrfs: Open code insert_extent_backref

No need to add a level of indirection for hiding a simple 'if'. Open
code insert_extent_backref in its sole caller. No functional changes.
Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/extent-tree.c

@@ -1189,24 +1189,6 @@ int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
-static int insert_extent_backref(struct btrfs_trans_handle *trans,
-				 struct btrfs_path *path,
-				 u64 bytenr, u64 parent, u64 root_objectid,
-				 u64 owner, u64 offset, int refs_to_add)
-{
-	int ret;
-	if (owner < BTRFS_FIRST_FREE_OBJECTID) {
-		BUG_ON(refs_to_add != 1);
-		ret = insert_tree_block_ref(trans, path, bytenr, parent,
-					    root_objectid);
-	} else {
-		ret = insert_extent_data_ref(trans, path, bytenr, parent,
-					     root_objectid, owner, offset,
-					     refs_to_add);
-	}
-	return ret;
-}
-
 static int remove_extent_backref(struct btrfs_trans_handle *trans,
 				 struct btrfs_path *path,
 				 struct btrfs_extent_inline_ref *iref,
@@ -1493,8 +1475,15 @@ static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
 	path->reada = READA_FORWARD;
 	path->leave_spinning = 1;
 	/* now insert the actual backref */
-	ret = insert_extent_backref(trans, path, bytenr, parent, root_objectid,
-				    owner, offset, refs_to_add);
+	if (owner < BTRFS_FIRST_FREE_OBJECTID) {
+		BUG_ON(refs_to_add != 1);
+		ret = insert_tree_block_ref(trans, path, bytenr, parent,
+					    root_objectid);
+	} else {
+		ret = insert_extent_data_ref(trans, path, bytenr, parent,
+					     root_objectid, owner, offset,
+					     refs_to_add);
+	}
 	if (ret)
 		btrfs_abort_transaction(trans, ret);
 out: