wsc: Handle beacon lost event

Handle the beacon loss event same as a disconnect: if any credentials
have been received try using them, otherwise fail.

src/wsc.c

@@ -364,6 +364,8 @@ static void wsc_netdev_event(struct netdev *netdev, enum netdev_event event,
 		break;
 	case NETDEV_EVENT_LOST_BEACON:
 		l_debug("Lost beacon");
+		wsc_connect_cb(device_get_netdev(wsc->device),
+				NETDEV_RESULT_HANDSHAKE_FAILED, wsc);
 		break;
 	case NETDEV_EVENT_DISCONNECT_BY_AP:
 		l_debug("Disconnect by AP");