platform/x86: asus-wmi: Use clamp_val() instead of open coded variant

There is no need to open code clamp_val() macro implementation.
Replace the corresponding lines with direct call to clamp_val().
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

drivers/platform/x86/asus-wmi.c

@@ -464,12 +464,7 @@ static void do_kbd_led_set(struct led_classdev *led_cdev, int value)
 	asus = container_of(led_cdev, struct asus_wmi, kbd_led);
 	max_level = asus->kbd_led.max_brightness;
 
-	if (value > max_level)
-		value = max_level;
-	else if (value < 0)
-		value = 0;
-
-	asus->kbd_led_wk = value;
+	asus->kbd_led_wk = clamp_val(value, 0, max_level);
 	kbd_led_update(asus);
 }