[SK_BUFF]: Introduce skb_reset_transport_header(skb)

For the common, open coded 'skb->h.raw = skb->data' operation, so that we can
later turn skb->h.raw into a offset, reducing the size of struct sk_buff in
64bit land while possibly keeping it as a pointer on 32bit.

This one touches just the most simple cases:

skb->h.raw = skb->data;
skb->h.raw = {skb_push|[__]skb_pull}()

The next ones will handle the slightly more "complex" cases.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/llc/llc_sap.c b/net/llc/llc_sap.c
index e76bbbf..2525165 100644
--- a/net/llc/llc_sap.c
+++ b/net/llc/llc_sap.c
@@ -39,7 +39,7 @@
 		skb_reset_mac_header(skb);
 		skb_reserve(skb, 50);
 		skb_reset_network_header(skb);
-		skb->h.raw = skb->data;
+		skb_reset_transport_header(skb);
 		skb->protocol = htons(ETH_P_802_2);
 		skb->dev      = dev;
 		if (sk != NULL)