ext4: clean up kerneldoc warnigns when building with W=1

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index d40ed94..92266a2 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -5676,8 +5676,8 @@ int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
 }
 
 /**
- * ext4_swap_extents - Swap extents between two inodes
- *
+ * ext4_swap_extents() - Swap extents between two inodes
+ * @handle: handle for this transaction
  * @inode1:	First inode
  * @inode2:	Second inode
  * @lblk1:	Start block for first inode