Huge pages: Use for_each_node instead of coding a loop over all nodes

There is one remaining case of a loop coded over all nodes. The use
of for_each_node will make the loop look like other loops over nodes.
We will also only inspect nodes that are online which may increase
performance.

Signed-off-by: Christoph Lameter <clameter@sgi.com>

Index: linux-2.6.20-rc6-mm3/mm/hugetlb.c
===================================================================
--- linux-2.6.20-rc6-mm3.orig/mm/hugetlb.c	2007-01-31 10:52:10.000000000 -0800
+++ linux-2.6.20-rc6-mm3/mm/hugetlb.c	2007-01-31 10:52:32.000000000 -0800
@@ -191,11 +191,11 @@ static void update_and_free_page(struct 
 #ifdef CONFIG_HIGHMEM
 static void try_to_free_low(unsigned long count)
 {
-	int i;
+	int node;
 
-	for (i = 0; i < MAX_NUMNODES; ++i) {
+	for_each_node(node) {
 		struct page *page, *next;
-		list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) {
+		list_for_each_entry_safe(page, next, &hugepage_freelists[node], lru) {
 			if (PageHighMem(page))
 				continue;
 			list_del(&page->lru);