[SK_BUFF]: Introduce ipv6_hdr(), remove skb->nh.ipv6h

Now the skb->nh union has just one member, .raw, i.e. it is just like the
skb->mac union, strange, no? I'm just leaving it like that till the transport
layer is done with, when we'll rename skb->mac.raw to skb->mac_header (or
->mac_header_offset?), ditto for ->{h,nh}.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/s390/net/qeth_main.c

@@ -4053,7 +4053,8 @@ qeth_fill_header(struct qeth_card *card, struct qeth_hdr *hdr,
 			       skb->dst->neighbour->primary_key, 16);
 		} else {
 			/* fill in destination address used in ip header */
-			memcpy(hdr->hdr.l3.dest_addr, &skb->nh.ipv6h->daddr, 16);
+			memcpy(hdr->hdr.l3.dest_addr,
+			       &ipv6_hdr(skb)->daddr, 16);
 		}
 	} else { /* passthrough */
                 if((skb->dev->type == ARPHRD_IEEE802_TR) &&