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/ordered-data.h b/fs/btrfs/ordered-data.h
index d1ddaef..dd27a0b 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -190,8 +190,7 @@
 void btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
 				 struct btrfs_root *root,
 				 struct inode *inode);
-void btrfs_wait_ordered_extents(struct btrfs_root *root,
-				int nocow_only, int delay_iput);
+void btrfs_wait_ordered_extents(struct btrfs_root *root, int delay_iput);
 int __init ordered_data_init(void);
 void ordered_data_exit(void);
 #endif