hv_netvsc: Fix VF register on vlan devices

BugLink: http://bugs.launchpad.net/bugs/1616677

Added a condition to avoid vlan devices with same MAC registering
as VF.
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit cb2911fe)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Acked-by: Kamal Mostafa <kamal@canonical.com>

drivers/net/hyperv/netvsc_drv.c

@@ -1500,6 +1500,10 @@ static int netvsc_netdev_event(struct notifier_block *this,
 {
 	struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
 
+	/* Avoid Vlan dev with same MAC registering as VF */
+	if (event_dev->priv_flags & IFF_802_1Q_VLAN)
+		return NOTIFY_DONE;
+
 	switch (event) {
 	case NETDEV_REGISTER:
 		return netvsc_register_vf(event_dev);