ext4: fix comments in ext4_swap_extents()

"mark_unwritten" in comment and "unwritten" in the function arguments
is mismatched.
Signed-off-by: Nzhenwei.pi <zhenwei.pi@youruncloud.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

fs/ext4/extents.c

@@ -5742,7 +5742,7 @@ int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
  * @lblk1:	Start block for first inode
  * @lblk2:	Start block for second inode
  * @count:	Number of blocks to swap
- * @mark_unwritten: Mark second inode's extents as unwritten after swap
+ * @unwritten: Mark second inode's extents as unwritten after swap
  * @erp:	Pointer to save error value
  *
  * This helper routine does exactly what is promise "swap extents". All other
@@ -5756,7 +5756,7 @@ int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
  */
 int
 ext4_swap_extents(handle_t *handle, struct inode *inode1,
-		     struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2,
+		  struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2,
 		  ext4_lblk_t count, int unwritten, int *erp)
 {
 	struct ext4_ext_path *path1 = NULL;