net: Do not fire linkwatch events until the device is registered.

Several device drivers try to do things like netif_carrier_off()
before register_netdev() is invoked. This is bogus, but too many
drivers do this to fix them all up in one go.

Reported-by: Folkert van Heusden <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/sched/sch_generic.c

···
 void netif_carrier_on(struct net_device *dev)
 {
 	if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
+		if (dev->reg_state == NETREG_UNINITIALIZED)
+			return;
 		linkwatch_fire_event(dev);
 		if (netif_running(dev))
 			__netdev_watchdog_up(dev);
···
  */
 void netif_carrier_off(struct net_device *dev)
 {
-	if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state))
+	if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
+		if (dev->reg_state == NETREG_UNINITIALIZED)
+			return;
 		linkwatch_fire_event(dev);
+	}
 }
 EXPORT_SYMBOL(netif_carrier_off);