Fix the VLAN_TAG_PRESENT in netvsc_recv_callback()

We should call __vlan_hwaccel_put_tag() only if the packet
comes from vlan, otherwise VLAN_TAG_PRESENT will always be
added.

Reported-by: Olaf Hering <olaf@aepfle.de>
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>

drivers/net/hyperv/netvsc_drv.c

@@ -285,7 +285,9 @@ int netvsc_recv_callback(struct hv_device *device_obj,
 
 	skb->protocol = eth_type_trans(skb, net);
 	skb->ip_summed = CHECKSUM_NONE;
-	__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), packet->vlan_tci);
+	if (packet->vlan_tci & VLAN_TAG_PRESENT)
+		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
+				       packet->vlan_tci);
 
 	net->stats.rx_packets++;
 	net->stats.rx_bytes += packet->total_data_buflen;