[PATCH] Change constant zero to NOTIFY_DONE in ratelimit_handler()

Change a hard-coded constant 0 to the symbolic equivalent NOTIFY_DONE in
the ratelimit_handler() CPU notifier handler function.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page-writeback.c

@@ -515,7 +515,7 @@ static int __cpuinit
 ratelimit_handler(struct notifier_block *self, unsigned long u, void *v)
 {
 	writeback_set_ratelimit();
-	return 0;
+	return NOTIFY_DONE;
 }
 
 static struct notifier_block __cpuinitdata ratelimit_nb = {