mm: Fix out-of-date comments which refers non-existent functions

do_file_page and do_no_page don't exist anymore, but some comments
still refers them. The patch fixes them by replacing them with
existing ones.

Signed-off-by: Ryota Ozaki <ozaki.ryota@gmail.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/mm/memory.c b/mm/memory.c
index 8e8c1832..8999b3d 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2115,10 +2115,10 @@
  * handle_pte_fault chooses page fault handler according to an entry
  * which was read non-atomically.  Before making any commitment, on
  * those architectures or configurations (e.g. i386 with PAE) which
- * might give a mix of unmatched parts, do_swap_page and do_file_page
+ * might give a mix of unmatched parts, do_swap_page and do_nonlinear_fault
  * must check under lock before unmapping the pte and proceeding
  * (but do_wp_page is only called after already making such a check;
- * and do_anonymous_page and do_no_page can safely check later on).
+ * and do_anonymous_page can safely check later on).
  */
 static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd,
 				pte_t *page_table, pte_t orig_pte)
@@ -2314,7 +2314,7 @@
 		 * bit after it clear all dirty ptes, but before a racing
 		 * do_wp_page installs a dirty pte.
 		 *
-		 * do_no_page is protected similarly.
+		 * __do_fault is protected similarly.
 		 */
 		if (!page_mkwrite) {
 			wait_on_page_locked(dirty_page);