relay: fix cpu offline problem

relay_open() will close allocated buffers when failed.
but if cpu offlined, some buffer will not be closed.
this patch fixed it.

and did cleanup for relay_reset() too.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/kernel/relay.c b/kernel/relay.c
index 8d13a78..32b0bef 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -400,7 +400,7 @@
 	}
 
 	mutex_lock(&relay_channels_mutex);
-	for_each_online_cpu(i)
+	for_each_possible_cpu(i)
 		if (chan->buf[i])
 			__relay_reset(chan->buf[i], 0);
 	mutex_unlock(&relay_channels_mutex);
@@ -611,10 +611,9 @@
 	return chan;
 
 free_bufs:
-	for_each_online_cpu(i) {
-		if (!chan->buf[i])
-			break;
-		relay_close_buf(chan->buf[i]);
+	for_each_possible_cpu(i) {
+		if (chan->buf[i])
+			relay_close_buf(chan->buf[i]);
 	}
 
 	kref_put(&chan->kref, relay_destroy_channel);