[IPV4]: ARP header annotated

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/if_arp.h

@@ -130,11 +130,11 @@ struct arpreq_old {
 
 struct arphdr
 {
-	unsigned short	ar_hrd;		/* format of hardware address	*/
-	unsigned short	ar_pro;		/* format of protocol address	*/
+	__be16		ar_hrd;		/* format of hardware address	*/
+	__be16		ar_pro;		/* format of protocol address	*/
 	unsigned char	ar_hln;		/* length of hardware address	*/
 	unsigned char	ar_pln;		/* length of protocol address	*/
-	unsigned short	ar_op;		/* ARP opcode (command)		*/
+	__be16		ar_op;		/* ARP opcode (command)		*/
 
 #if 0
 	 /*