[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/net/ipv4/ah4.c b/net/ipv4/ah4.c
index e1bb9e0a..6da8ff5 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -181,9 +181,9 @@
 		}
 	}
 	((struct iphdr*)work_buf)->protocol = ah->nexthdr;
-	skb->nh.raw += ah_hlen;
+	skb->network_header += ah_hlen;
 	memcpy(skb_network_header(skb), work_buf, ihl);
-	skb->h.raw = skb->nh.raw;
+	skb->transport_header = skb->network_header;
 	__skb_pull(skb, ah_hlen + ihl);
 
 	return 0;