greybus: svc: return proper error code on watchdog create error

When the watchdog is not created properly, we need to propagate the
error for this and not just return success.
Reported-by: Rui Miguel Silva <rui.silva@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/svc.c

@@ -441,6 +441,7 @@ static int gb_svc_hello(struct gb_operation *op)
 		dev_err(&svc->dev, "failed to create watchdog: %d\n", ret);
 		input_unregister_device(svc->input);
 		device_del(&svc->dev);
+		return ret;
 	}
 
 	return 0;