[AX25] Introduce ax25_type_trans

Replacing the open coded equivalents and making ax25 look more like
a linux network protocol, i.e. more similar to inet.

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ax25.h b/include/net/ax25.h
index 875edbb..9e6368a 100644
--- a/include/net/ax25.h
+++ b/include/net/ax25.h
@@ -220,6 +220,14 @@
 	}
 }
 
+static inline unsigned short ax25_type_trans(struct sk_buff *skb, struct net_device *dev)
+{
+	skb->dev      = dev;
+	skb->pkt_type = PACKET_HOST;
+	skb->mac.raw  = skb->data;
+	return htons(ETH_P_AX25);
+}
+
 /* af_ax25.c */
 extern struct hlist_head ax25_list;
 extern spinlock_t ax25_list_lock;