[IPV6]: Use skb->nh.ipv6h instead of casting skb->nh.raw

nh.ipv6h is there exactly for this reason! Use it while it exists ;-)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/exthdrs.c

@@ -200,7 +200,7 @@ static int ipv6_dest_hao(struct sk_buff **skbp, int optoff)
 	struct sk_buff *skb = *skbp;
 	struct ipv6_destopt_hao *hao;
 	struct inet6_skb_parm *opt = IP6CB(skb);
-	struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb->nh.raw;
+	struct ipv6hdr *ipv6h = skb->nh.ipv6h;
 	struct in6_addr tmp_addr;
 	int ret;