hugetlb, rmap: use hugepage_add_new_anon_rmap() in hugetlb_cow()

Obviously, setting anon_vma for COWed hugepage should be done
by hugepage_add_new_anon_rmap() to scan vmas faster.
This patch fixes it.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/hugetlb.c

@@ -2404,7 +2404,7 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
 		set_huge_pte_at(mm, address, ptep,
 				make_huge_pte(vma, new_page, 1));
 		page_remove_rmap(old_page);
-		hugepage_add_anon_rmap(new_page, vma, address);
+		hugepage_add_new_anon_rmap(new_page, vma, address);
 		/* Make the old page be freed below */
 		new_page = old_page;
 		mmu_notifier_invalidate_range_end(mm,