vlan: Match underlying dev carrier on vlan add

When adding a new vlan, if the underlying interface has no carrier,
then the newly added vlan interface should also have no carrier.
At present, this is not true - the newly added vlan is added with
carrier up.  Fix by checking state of real device.

Signed-off-by: Phil Oester <kernel@linuxace.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/8021q/vlan_dev.c

@@ -510,7 +510,8 @@ static int vlan_dev_open(struct net_device *dev)
 	if (vlan->flags & VLAN_FLAG_GVRP)
 		vlan_gvrp_request_join(dev);
 
-	netif_carrier_on(dev);
+	if (netif_carrier_ok(real_dev))
+		netif_carrier_on(dev);
 	return 0;
 
 clear_allmulti: