swap_prefetch: nr_mapped conversion

This is separate on request by Andrew.

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

Index: linux-2.6.17-rc6-cl/mm/swap_prefetch.c
===================================================================
--- linux-2.6.17-rc6-cl.orig/mm/swap_prefetch.c	2006-06-10 22:04:26.763047220 -0700
+++ linux-2.6.17-rc6-cl/mm/swap_prefetch.c	2006-06-12 11:29:47.664697453 -0700
@@ -394,7 +394,8 @@ static int prefetch_suitable(void)
 		 * even if the slab is being allocated on a remote node. This
 		 * would be expensive to fix and not of great significance.
 		 */
-		limit = ps.nr_mapped + ps.nr_slab + ps.nr_dirty +
+		limit = node_page_state(node, NR_MAPPED) +
+			ps.nr_slab + ps.nr_dirty +
 			ps.nr_unstable + total_swapcache_pages;
 		if (limit > ns->prefetch_watermark) {
 			node_clear(node, sp_stat.prefetch_nodes);