[TIPC]: Fix 64-bit build warnings.

When storing u32 values in a pointer, need to do
some long casts to keep GCC happy.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/port.c b/net/tipc/port.c
index bb94046..66caca7 100644
--- a/net/tipc/port.c
+++ b/net/tipc/port.c
@@ -1234,7 +1234,8 @@
 	p_ptr->publ.connected = 1;
 	k_start_timer(&p_ptr->timer, p_ptr->probing_interval);
 
-	nodesub_subscribe(&p_ptr->subscription,peer->node, (void *)ref,
+	nodesub_subscribe(&p_ptr->subscription,peer->node,
+			  (void *)(unsigned long)ref,
 			  (net_ev_handler)port_handle_node_down);
 	res = TIPC_OK;
 exit: