[NET]: Annotate h_proto in struct ethhdr

The protocol field in ethernet headers is big-endian and should be
annotated as such.  This patch allows detection of missing ntohs() calls
on the ethernet protocol field when sparse is run with __CHECK_ENDIAN__
defined.

This is a revised version that includes <linux/types.h> so that the
userspace programs are not confused by __be16.  Thanks to David S.
Miller.
Signed-off-by: NPavel Roskin <proski@gnu.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/linux/if_ether.h

@@ -21,6 +21,8 @@
 #ifndef _LINUX_IF_ETHER_H
 #define _LINUX_IF_ETHER_H
 
+#include <linux/types.h>
+
 /*
  *	IEEE 802.3 Ethernet magic constants.  The frame sizes omit the preamble
  *	and FCS/CRC (frame check sequence). 
@@ -100,7 +102,7 @@
 struct ethhdr {
 	unsigned char	h_dest[ETH_ALEN];	/* destination eth addr	*/
 	unsigned char	h_source[ETH_ALEN];	/* source ether addr	*/
-	unsigned short	h_proto;		/* packet type ID field	*/
+	__be16		h_proto;		/* packet type ID field	*/
 } __attribute__((packed));
 
 #ifdef __KERNEL__