leds: leds-ss4200: replace strict_strtoul() with kstrtoul()

The usage of strict_strtoul() is not preferred, because
strict_strtoul() is obsolete. Thus, kstrtoul() should be
used.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

drivers/leds/leds-ss4200.c

@@ -459,7 +459,7 @@ static ssize_t nas_led_blink_store(struct device *dev,
 	struct led_classdev *led = dev_get_drvdata(dev);
 	unsigned long blink_state;
 
-	ret = strict_strtoul(buf, 10, &blink_state);
+	ret = kstrtoul(buf, 10, &blink_state);
 	if (ret)
 		return ret;