leds: leds-pwm: Simplify cleanup code

The code looks more nicer if we use:

while (i--)

instead:
if (i > 0)
	for (i = i - 1; i >= 0; i--)
Signed-off-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: NBryan Wu <cooloney@gmail.com>

drivers/leds/leds-pwm.c

@@ -104,10 +104,8 @@ static int led_pwm_probe(struct platform_device *pdev)
 	return 0;
 
 err:
-	if (i > 0) {
-		for (i = i - 1; i >= 0; i--)
-			led_classdev_unregister(&priv->leds[i].cdev);
-	}
+	while (i--)
+		led_classdev_unregister(&priv->leds[i].cdev);
 
 	return ret;
 }