mm/migrate.c: kill anon local variable from migrate_page_copy

commit 01b1ae63 ("memcg: simple migration handling") removed
mem_cgroup_uncharge_cache_page() call from migrate_page_copy.  Local
variable `anon' is now unused.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/migrate.c

@@ -275,8 +275,6 @@ static int migrate_page_move_mapping(struct address_space *mapping,
  */
 static void migrate_page_copy(struct page *newpage, struct page *page)
 {
-	int anon;
-
 	copy_highpage(newpage, page);
 
 	if (PageError(page))
@@ -313,8 +311,6 @@ static void migrate_page_copy(struct page *newpage, struct page *page)
 	ClearPageSwapCache(page);
 	ClearPagePrivate(page);
 	set_page_private(page, 0);
-	/* page->mapping contains a flag for PageAnon() */
-	anon = PageAnon(page);
 	page->mapping = NULL;
 
 	/*