ppp: Do not free not yet unregistered net device.

An error path in ppp_create_interface() lacks one and may
BUG in free_netdev() checking for proper dev->reg_state.

Signed-off-by: Pavel Emelyanov <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ppp_generic.c

···
 
 out3:
 	atomic_dec(&ppp_unit_count);
+	unregister_netdev(dev);
 out2:
 	mutex_unlock(&all_ppp_mutex);
 	free_netdev(dev);