be2net: take care of __vlan_put_tag return value

The driver should use return value of __vlan_put_tag with appropriate
NULL-check instead of old skb pointer.
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/emulex/benet/be_main.c

@@ -759,7 +759,8 @@ static struct sk_buff *be_insert_vlan_in_pkt(struct be_adapter *adapter,
 
 	if (vlan_tx_tag_present(skb)) {
 		vlan_tag = be_get_tx_vlan_tag(adapter, skb);
-		__vlan_put_tag(skb, vlan_tag);
+		skb = __vlan_put_tag(skb, vlan_tag);
+		if (skb)
 			skb->vlan_tci = 0;
 	}