[NET]: Kill skb->list

Remove the "list" member of struct sk_buff, as it is entirely
redundant.  All SKB list removal callers know which list the
SKB is on, so storing this in sk_buff does nothing other than
taking up some space.

Two tricky bits were SCTP, which I took care of, and two ATM
drivers which Francois Romieu <romieu@fr.zoreil.com> fixed
up.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
diff --git a/net/decnet/af_decnet.c b/net/decnet/af_decnet.c
index acdd18e..0c30409 100644
--- a/net/decnet/af_decnet.c
+++ b/net/decnet/af_decnet.c
@@ -1763,7 +1763,7 @@
 		nskb = skb->next;
 
 		if (skb->len == 0) {
-			skb_unlink(skb);
+			skb_unlink(skb, queue);
 			kfree_skb(skb);
 			/* 
 			 * N.B. Don't refer to skb or cb after this point