[SK_BUFF]: Introduce skb_mac_header()

For the places where we need a pointer to the mac header, it is still legal to
touch skb->mac.raw directly if just adding to, subtracting from or setting it
to another layer header.

This one also converts some more cases to skb_reset_mac_header() that my
regex missed as it had no spaces before nor after '=', ugh.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/appletalk/ddp.c b/net/appletalk/ddp.c
index 32b8270..934f259 100644
--- a/net/appletalk/ddp.c
+++ b/net/appletalk/ddp.c
@@ -1484,7 +1484,7 @@
 		     struct packet_type *pt, struct net_device *orig_dev)
 {
 	/* Expand any short form frames */
-	if (skb->mac.raw[2] == 1) {
+	if (skb_mac_header(skb)[2] == 1) {
 		struct ddpehdr *ddp;
 		/* Find our address */
 		struct atalk_addr *ap = atalk_find_dev_addr(dev);
@@ -1510,8 +1510,8 @@
 		 * we write the network numbers !
 		 */
 
-		ddp->deh_dnode = skb->mac.raw[0];     /* From physical header */
-		ddp->deh_snode = skb->mac.raw[1];     /* From physical header */
+		ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
+		ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
 
 		ddp->deh_dnet  = ap->s_net;	/* Network number */
 		ddp->deh_snet  = ap->s_net;