qeth: fix build error caused by VLAN changes

Adrian Bunk reports this build error:

CC      drivers/s390/net/qeth_l3_main.o
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/s390/net/qeth_l3_main.c:
In function 'qeth_l3_hard_start_xmit':
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/s390/net/qeth_l3_main.c:
2654: error: implicit declaration of function 'VLAN_TX_SKB_CB'
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/s390/net/qeth_l3_main.c:
2654: error: invalid type argument of '->' (have 'int')
make[3]: *** [drivers/s390/net/qeth_l3_main.o] Error 1

The intention of the driver appears to be to invalidate the VLAN tag.
Change it to set skb->vlan_tci to zero, which has the same effect.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/s390/net/qeth_l3_main.c

@@ -2651,7 +2651,7 @@ static int qeth_l3_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 			tag = (u16 *)(new_skb->data + 12);
 			*tag = __constant_htons(ETH_P_8021Q);
 			*(tag + 1) = htons(vlan_tx_tag_get(new_skb));
-			VLAN_TX_SKB_CB(new_skb)->magic = 0;
+			new_skb->vlan_tci = 0;
 		}
 	}