ext4: correct comments for ext4_free_blocks()

metadata is not parameter of ext4_free_blocks() any more.
Signed-off-by: NYongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

fs/ext4/mballoc.c

@@ -4448,7 +4448,7 @@ ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
  * @inode:		inode
  * @block:		start physical block to free
  * @count:		number of blocks to count
- * @metadata: 		Are these metadata blocks
+ * @flags:		flags used by ext4_free_blocks
  */
 void ext4_free_blocks(handle_t *handle, struct inode *inode,
 		      struct buffer_head *bh, ext4_fsblk_t block,