mm: move page->mem_cgroup bad page handling into generic code

mm: move page->mem_cgroup bad page handling into generic code

Now that the external page_cgroup data structure and its lookup is
gone, let the generic bad_page() check for page->mem_cgroup sanity.

Signed-off-by: Johannes Weiner <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Acked-by: Vladimir Davydov <[email protected]>
Acked-by: David S. Miller <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>