net: tcp2: Use pointer to slist node

Instead of forcing the slist node to be first in the tcp struct,
use the pointer to node when accessing the slist. This way we
can change the ordering of fields in tcp struct.

Signed-off-by: Jukka Rissanen <[email protected]>

Author: jukkar

subsys/net/ip/tcp2.c

@@ -326,7 +326,7 @@ static int tcp_conn_unref(struct tcp *conn)
 
 	k_delayed_work_cancel(&conn->timewait_timer);
 
-	sys_slist_find_and_remove(&tcp_conns, (sys_snode_t *)conn);
+	sys_slist_find_and_remove(&tcp_conns, &conn->next);
 
 	memset(conn, 0, sizeof(*conn));
 
@@ -893,7 +893,7 @@ static struct tcp *tcp_conn_alloc(void)
 
 	tcp_conn_ref(conn);
 
-	sys_slist_append(&tcp_conns, (sys_snode_t *)conn);
+	sys_slist_append(&tcp_conns, &conn->next);
 out:
 	NET_DBG("conn: %p", conn);