[SK_BUFF]: unions of just one member don't get anything done, kill them

Renaming skb->h to skb->transport_header, skb->nh to skb->network_header and
skb->mac to skb->mac_header, to match the names of the associated helpers
(skb[_[re]set]_{transport,network,mac}_header).

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/arcnet/arcnet.c b/drivers/net/arcnet/arcnet.c
index 83004fd..681e20b 100644
--- a/drivers/net/arcnet/arcnet.c
+++ b/drivers/net/arcnet/arcnet.c
@@ -519,9 +519,12 @@
 		 * real header when we do rebuild_header.
 		 */
 		*(uint16_t *) skb_push(skb, 2) = type;
-		if (skb->nh.raw - skb->mac.raw != 2)
+		/*
+		 * XXX: Why not use skb->mac_len?
+		 */
+		if (skb->network_header - skb->mac_header != 2)
 			BUGMSG(D_NORMAL, "arcnet_header: Yikes!  diff (%d) is not 2!\n",
-			       (int)(skb->nh.raw - skb->mac.raw));
+			       (int)(skb->network_header - skb->mac_header));
 		return -2;	/* return error -- can't transmit yet! */
 	}
 	else {
@@ -554,11 +557,13 @@
 	unsigned short type;
 	uint8_t daddr=0;
 	struct ArcProto *proto;
-
-	if (skb->nh.raw - skb->mac.raw != 2) {
+	/*
+	 * XXX: Why not use skb->mac_len?
+	 */
+	if (skb->network_header - skb->mac_header != 2) {
 		BUGMSG(D_NORMAL,
-		     "rebuild_header: shouldn't be here! (hdrsize=%d)\n",
-		     (int)(skb->nh.raw - skb->mac.raw));
+		       "rebuild_header: shouldn't be here! (hdrsize=%d)\n",
+		       (int)(skb->network_header - skb->mac_header));
 		return 0;
 	}
 	type = *(uint16_t *) skb_pull(skb, 2);