test: dm: Test for default led naming

This modifies the existing led test to check for default led naming as
added in the previous patch.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/sandbox/dts/test.dts

@@ -559,7 +559,7 @@
 
 		default_off {
 			gpios = <&gpio_a 6 0>;
-			label = "sandbox:default_off";
+			/* label intentionally omitted */
 			default-state = "off";
 		};
 	};

test/dm/led.c

@@ -40,7 +40,8 @@ static int dm_test_led_default_state(struct unit_test_state *uts)
 	ut_assertok(led_get_by_label("sandbox:default_on", &dev));
 	ut_asserteq(LEDST_ON, led_get_state(dev));
 
-	ut_assertok(led_get_by_label("sandbox:default_off", &dev));
+	/* Also tests default label behaviour */
+	ut_assertok(led_get_by_label("default_off", &dev));
 	ut_asserteq(LEDST_OFF, led_get_state(dev));
 
 	return 0;