platform/x86: asus-wmi: Fix preserving keyboard backlight intensity on load

The error code and return value are mixed up. The intensity is always set
to 0 on load as kbd_led_read returns either 0 or negative value. To
reproduce set backlight to maximum, reload driver and try to increase it
using keyboard hotkey, the intensity will drop as a result. Correct the
implementation.
Signed-off-by: Yurii Pavlovskyi <yurii.pavlovskyi@gmail.com>
Reviewed-by: Daniel Drake <drake@endlessm.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

drivers/platform/x86/asus-wmi.c

@@ -595,8 +595,7 @@ static int asus_wmi_led_init(struct asus_wmi *asus)
 			goto error;
 	}
 
-	led_val = kbd_led_read(asus, NULL, NULL);
-	if (led_val >= 0) {
+	if (!kbd_led_read(asus, &led_val, NULL)) {
 		asus->kbd_led_wk = led_val;
 		asus->kbd_led.name = "asus::kbd_backlight";
 		asus->kbd_led.flags = LED_BRIGHT_HW_CHANGED;