mempolicy: apply page table walker on queue_pages_range()

mempolicy: apply page table walker on queue_pages_range()

queue_pages_range() does page table walking in its own way now, so this
patch rewrites it with walk_page_range().  One difficulty was that
queue_pages_range() needed to check vmas to determine whether we queue
pages from a given vma or skip it.  Now we have test_walk() callback in
mm_walk for that purpose, so we can do the replacement cleanly.
queue_pages_test_walk() depends on not only the current vma but also the
previous one, so we use queue_pages->prev to keep it.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Cliff Wickman <cpw@sgi.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>