[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>
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index 6e6b57a..7aff380 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -191,7 +191,7 @@
 	skb->ip_summed = CHECKSUM_NONE;
 
 	esph = (struct ipv6_esp_hdr*)skb->data;
-	iph = skb->nh.ipv6h;
+	iph = ipv6_hdr(skb);
 
 	/* Get ivec. This can be wrong, check against another impls. */
 	if (esp->conf.ivlen)