mm: make gather_stats() type-safe and remove forward declaration

Improve the prototype of gather_stats() to take a struct numa_maps as
argument instead of a generic void *.  Update all callers to make the
required type explicit.

Since gather_stats() is not needed before its definition and is scheduled
to be moved out of mempolicy.c the declaration is removed as well.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mempolicy.c

@@ -456,7 +456,6 @@ static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
 	},
 };
 
-static void gather_stats(struct page *, void *, int pte_dirty);
 static void migrate_page_add(struct page *page, struct list_head *pagelist,
 				unsigned long flags);
 
@@ -2539,9 +2538,8 @@ struct numa_maps {
 	unsigned long node[MAX_NUMNODES];
 };
 
-static void gather_stats(struct page *page, void *private, int pte_dirty)
+static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty)
 {
-	struct numa_maps *md = private;
 	int count = page_mapcount(page);
 
 	md->pages++;
@@ -2634,6 +2632,7 @@ static void check_huge_range(struct vm_area_struct *vma,
 static int gather_hugetbl_stats(pte_t *pte, unsigned long hmask,
 		unsigned long addr, unsigned long end, struct mm_walk *walk)
 {
+	struct numa_maps *md;
 	struct page *page;
 
 	if (pte_none(*pte))
@@ -2643,7 +2642,8 @@ static int gather_hugetbl_stats(pte_t *pte, unsigned long hmask,
 	if (!page)
 		return 0;
 
-	gather_stats(page, walk->private, pte_dirty(*pte));
+	md = walk->private;
+	gather_stats(page, md, pte_dirty(*pte));
 	return 0;
 }