[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/arch/um/drivers/pcap_kern.c b/arch/um/drivers/pcap_kern.c
index e67362a..9488493 100644
--- a/arch/um/drivers/pcap_kern.c
+++ b/arch/um/drivers/pcap_kern.c
@@ -36,7 +36,7 @@
 {
 	*skb = ether_adjust_skb(*skb, ETH_HEADER_OTHER);
 	if(*skb == NULL) return(-ENOMEM);
-	return(pcap_user_read(fd, (*skb)->mac.raw, 
+	return(pcap_user_read(fd, skb_mac_header(*skb),
 			      (*skb)->dev->mtu + ETH_HEADER_OTHER,
 			      (struct pcap_data *) &lp->user));
 }