bridge: simplify multicast_add_router

By coding slightly differently, there are only two cases
to deal with: add at head and add after previous entry.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_multicast.c

@@ -1039,22 +1039,25 @@ static int br_ip6_multicast_mld2_report(struct net_bridge *br,
 }
 #endif
 
+/*
+ * Add port to rotuer_list
+ *  list is maintained ordered by pointer value
+ *  and locked by br->multicast_lock and RCU
+ */
 static void br_multicast_add_router(struct net_bridge *br,
 				    struct net_bridge_port *port)
 {
 	struct net_bridge_port *p;
-	struct hlist_node *n, *last = NULL;
+	struct hlist_node *n, *slot = NULL;
 
 	hlist_for_each_entry(p, n, &br->router_list, rlist) {
-		if ((unsigned long) port >= (unsigned long) p) {
-			hlist_add_before_rcu(n, &port->rlist);
-			return;
-		}
-		last = n;
+		if ((unsigned long) port >= (unsigned long) p)
+			break;
+		slot = n;
 	}
 
-	if (last)
-		hlist_add_after_rcu(last, &port->rlist);
+	if (slot)
+		hlist_add_after_rcu(slot, &port->rlist);
 	else
 		hlist_add_head_rcu(&port->rlist, &br->router_list);
 }