[AX.25]: Fix packet socket crash

Since changeset 98a82febb6 AX.25 is passing
received IP and ARP packets to the stack through netif_rx() but we don't
set the skb->mac.raw to right value which may result in a crash with
applications that use a packet socket.

Signed-off-by: Ralf Baechle DL5RB <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/netrom/nr_dev.c

@@ -58,7 +58,7 @@ int nr_rx_ip(struct sk_buff *skb, struct net_device *dev)
 
 	/* Spoof incoming device */
 	skb->dev      = dev;
-	skb->h.raw    = skb->data;
+	skb->mac.raw  = skb->nh.raw;
 	skb->nh.raw   = skb->data;
 	skb->pkt_type = PACKET_HOST;