[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/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index dd30dd1..a4d1eb9 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -505,7 +505,7 @@
 
 	/* Link BUFF into the send queue. */
 	skb_header_release(buff);
-	__skb_append(skb, buff);
+	__skb_append(skb, buff, &sk->sk_write_queue);
 
 	return 0;
 }
@@ -893,7 +893,7 @@
 
 	/* Link BUFF into the send queue. */
 	skb_header_release(buff);
-	__skb_append(skb, buff);
+	__skb_append(skb, buff, &sk->sk_write_queue);
 
 	return 0;
 }
@@ -1238,7 +1238,7 @@
 		       tcp_skb_pcount(next_skb) != 1);
 
 		/* Ok.  We will be able to collapse the packet. */
-		__skb_unlink(next_skb, next_skb->list);
+		__skb_unlink(next_skb, &sk->sk_write_queue);
 
 		memcpy(skb_put(skb, next_skb_size), next_skb->data, next_skb_size);