[SK_BUFF]: Introduce skb_transport_header(skb)

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

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 880eb7b..dcb3a91 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -328,7 +328,7 @@
 		case TCF_LAYER_NETWORK:
 			return skb_network_header(skb);
 		case TCF_LAYER_TRANSPORT:
-			return skb->h.raw;
+			return skb_transport_header(skb);
 	}
 
 	return NULL;