netns: add namespace parameter to rt_cache_flush

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 20c515a..29df75a 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -1197,7 +1197,7 @@
 	switch (event) {
 	case NETDEV_CHANGEADDR:
 		neigh_changeaddr(&arp_tbl, dev);
-		rt_cache_flush(0);
+		rt_cache_flush(dev_net(dev), 0);
 		break;
 	default:
 		break;