[BRIDGE] br_if: Fix oops in port_carrier_check

Signed-off-by: Jarek Poplawski <jarkao2@o2.pl>
Acked-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_notify.c b/net/bridge/br_notify.c
index 8cd3e42..3311c4e3 100644
--- a/net/bridge/br_notify.c
+++ b/net/bridge/br_notify.c
@@ -56,7 +56,9 @@
 
 	case NETDEV_CHANGE:
 		if (br->dev->flags & IFF_UP)
-			schedule_delayed_work(&p->carrier_check, BR_PORT_DEBOUNCE);
+			if (schedule_delayed_work(&p->carrier_check,
+						BR_PORT_DEBOUNCE))
+				dev_hold(dev);
 		break;
 
 	case NETDEV_FEAT_CHANGE: