Fix typo in do_no_page vs invalidate race fix patch.

Index: linux-2.6/mm/truncate.c
===================================================================
--- linux-2.6.orig/mm/truncate.c
+++ linux-2.6/mm/truncate.c
@@ -235,7 +235,7 @@ void truncate_inode_pages_range(struct a
 			wait_on_page_writeback(page);
 			if (page_mapped(page)) {
 				unmap_mapping_range(mapping,
-				  (loff_t)page_index<<PAGE_CACHE_SHIFT,
+				  (loff_t)page->index<<PAGE_CACHE_SHIFT,
 				  PAGE_CACHE_SIZE, 0);
 			}
 			if (page->index > next)