[SK_BUFF]: Use skb_reset_network_header in skb_push cases

skb_push updates and returns skb->data, so we can just call
skb_reset_network_header after the call to skb_push.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 0477728..62883d4 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -554,7 +554,8 @@
 	}
 
 	skb->h.raw = skb->nh.raw;
-	skb->nh.raw = skb_push(skb, sizeof(struct iphdr));
+	skb_push(skb, sizeof(struct iphdr));
+	skb_reset_network_header(skb);
 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 	IPCB(skb)->flags = 0;
 	dst_release(skb->dst);