mm: use walk_page_range() instead of custom page table walking code

mm: use walk_page_range() instead of custom page table walking code

Converting show_numa_map() to use the generic routine decouples the
function from mempolicy.c, allowing it to be moved out of the mm subsystem
and into fs/proc.

Also, include KSM pages in /proc/pid/numa_maps statistics.  The pagewalk
logic implemented by check_pte_range() failed to account for such pages as
they were not applicable to the page migration case.

Signed-off-by: Stephen Wilson <[email protected]>
Reviewed-by: KOSAKI Motohiro <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Lee Schermerhorn <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Christoph Lameter <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>