bridge: multicast: start querier timer when running user-space stp

When STP is running in user-space and querier is configured, the
querier timer is not started when a port goes to a non-blocking state.
This patch unifies the user- and kernel-space stp multicast port enable
path and enables it in all states different from blocking. Note that when a
port goes in BR_STATE_DISABLED it's not enabled because that is handled
in the beginning of the port list loop.
Signed-off-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/bridge/br_stp.c

@@ -428,7 +428,6 @@ static void br_make_forwarding(struct net_bridge_port *p)
 	else
 		br_set_state(p, BR_STATE_LEARNING);
 
-	br_multicast_enable_port(p);
 	br_log_state(p);
 	br_ifinfo_notify(RTM_NEWLINK, p);
 
@@ -462,6 +461,8 @@ void br_port_state_selection(struct net_bridge *br)
 			}
 		}
 
+		if (p->state != BR_STATE_BLOCKING)
+			br_multicast_enable_port(p);
 		if (p->state == BR_STATE_FORWARDING)
 			++liveports;
 	}