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/extent-tree.c b/fs/btrfs/extent-tree.c
index 27a6b3e..a3a902f 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3722,7 +3722,7 @@
 	if (delalloc_bytes == 0) {
 		if (trans)
 			return;
-		btrfs_wait_ordered_extents(root, 0, 0);
+		btrfs_wait_ordered_extents(root, 0);
 		return;
 	}
 
@@ -3748,7 +3748,7 @@
 
 		loops++;
 		if (wait_ordered && !trans) {
-			btrfs_wait_ordered_extents(root, 0, 0);
+			btrfs_wait_ordered_extents(root, 0);
 		} else {
 			time_left = schedule_timeout_killable(1);
 			if (time_left)