[PATCH] mm: isolate_lru_pages() scan count fix

In isolate_lru_pages(), *scanned reports one more scan because the scan
counter is increased one more time on exit of the while-loop.

Change the while-loop to for-loop to fix it.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Wu Fengguang <wfg@mail.ustc.edu.cn>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

mm/vmscan.c

@@ -1074,9 +1074,9 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 {
 	unsigned long nr_taken = 0;
 	struct page *page;
-	unsigned long scan = 0;
+	unsigned long scan;
 
-	while (scan++ < nr_to_scan && !list_empty(src)) {
+	for (scan = 0; scan < nr_to_scan && !list_empty(src); scan++) {
 		struct list_head *target;
 		page = lru_to_page(src);
 		prefetchw_prev_lru_page(page, src, flags);