Btrfs: kill obsolete arguments in btrfs_wait_ordered_extents

nocow_only is now an obsolete argument.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index e4bfac8..c9265a6 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1475,7 +1475,7 @@
 
 		if (flush_on_commit || snap_pending) {
 			btrfs_start_delalloc_inodes(root, 1);
-			btrfs_wait_ordered_extents(root, 0, 1);
+			btrfs_wait_ordered_extents(root, 1);
 		}
 
 		ret = btrfs_run_delayed_items(trans, root);