fbd-dev-led-multicolor: Ignore LEDs that don't have three values

We assume that multicolor LEDs are RGB so reject those that don't
have three components.

E.g. the Framework Laptop exposes a power button LED as multicolor
that only has a white component. This way it gets treated as single color LED.

Signed-off-by: Guido Günther <agx@sigxcpu.org>

src/fbd-dev-led-multicolor.c

@@ -57,6 +57,13 @@ fbd_dev_led_multicolor_probe (FbdDevLed *led, GError **error)
     return FALSE;
   }
 
+  if (g_strv_length ((GStrv)index) != 3) {
+    g_set_error (error,
+                 G_FILE_ERROR, G_FILE_ERROR_FAILED,
+                 "%s is no multicolor RGB LED", name);
+    return FALSE;
+  }
+
   max_brightness = g_udev_device_get_sysfs_attr_as_int (dev, LED_MAX_BRIGHTNESS_ATTR);
   if (!max_brightness) {
     g_set_error (error,