[BRIDGE]: flush forwarding table when device carrier off

Flush the forwarding table when carrier is lost. This helps for
availability because we don't want to forward to a downed device and
new packets may come in on other links.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
index 14cd025..d294224 100644
--- a/net/bridge/br_stp_if.c
+++ b/net/bridge/br_stp_if.c
@@ -113,6 +113,8 @@
 	del_timer(&p->forward_delay_timer);
 	del_timer(&p->hold_timer);
 
+	br_fdb_delete_by_port(br, p, 0);
+
 	br_configuration_update(br);
 
 	br_port_state_selection(br);