mm: page_alloc: squash page_is_consistent()

Squash the page_is_consistent() into bad_range() as there is only one
caller.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Kefeng Wang <[e-mail]>
Reviewed-by: Mike Rapoport (IBM) <[e-mail]>
Cc: David Hildenbrand <[e-mail]>
Cc: "Huang, Ying" <[e-mail]>
Cc: Iurii Zaikin <[e-mail]>
Cc: Kees Cook <[e-mail]>
Cc: Len Brown <[e-mail]>
Cc: Luis Chamberlain <[e-mail]>
Cc: Oscar Salvador <[e-mail]>
Cc: Pavel Machek <[e-mail]>
Cc: Rafael J. Wysocki <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

mm/page_alloc.c

···
 	return ret;
 }
 
-static int page_is_consistent(struct zone *zone, struct page *page)
-{
-	if (zone != page_zone(page))
-		return 0;
-
-	return 1;
-}
 /*
  * Temporary debugging check for pages not lying within a given zone.
  */
···
 {
 	if (page_outside_zone_boundaries(zone, page))
 		return 1;
-	if (!page_is_consistent(zone, page))
+	if (zone != page_zone(page))
 		return 1;
 
 	return 0;