[SK_BUFF]: Introduce skb_set_transport_header

For the cases where the transport header is being set to a offset from
skb->data.

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

net/ax25/ax25_in.c

@@ -233,7 +233,7 @@ static int ax25_rcv(struct sk_buff *skb, struct net_device *dev,
 
 	/* UI frame - bypass LAPB processing */
 	if ((*skb->data & ~0x10) == AX25_UI && dp.lastrepeat + 1 == dp.ndigi) {
-		skb->h.raw = skb->data + 2;		/* skip control and pid */
+		skb_set_transport_header(skb, 2); /* skip control and pid */
 
 		ax25_send_to_raw(&dest, skb, skb->data[1]);