mm,numa: fix update_mmu_cache_pmd call

This build error is currently hidden by the fact that the x86
implementation of 'update_mmu_cache_pmd()' is a macro that doesn't use
its last argument, but commit b32967ff ("mm: numa: Add THP migration
for the NUMA working set scanning fault case") introduced a call with
the wrong third argument.

In the akpm tree, it causes this build error:

  mm/migrate.c: In function 'migrate_misplaced_transhuge_page_put':
  mm/migrate.c:1666:2: error: incompatible type for argument 3 of 'update_mmu_cache_pmd'
  arch/x86/include/asm/pgtable.h:792:20: note: expected 'struct pmd_t *' but argument is of type 'pmd_t'

Fix it.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/migrate.c

@@ -1734,7 +1734,7 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
 	page_add_new_anon_rmap(new_page, vma, haddr);
 
 	set_pmd_at(mm, haddr, pmd, entry);
-	update_mmu_cache_pmd(vma, address, entry);
+	update_mmu_cache_pmd(vma, address, &entry);
 	page_remove_rmap(page);
 	/*
 	 * Finish the charge transaction under the page table lock to