thinkpad_acpi: Use acpi_video_handles_brightness_key_presses()

Use the new acpi_video_handles_brightness_key_presses function to check
if we should report brightness key-presses.

This makes the code both easier to read and makes it properly report
key-presses when acpi-video is not reporting them for reasons other
then the backlight type being vendor.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/platform/x86/thinkpad_acpi.c

@@ -3488,7 +3488,7 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
 	/* Do not issue duplicate brightness change events to
 	 * userspace. tpacpi_detect_brightness_capabilities() must have
 	 * been called before this point  */
-	if (acpi_video_get_backlight_type() != acpi_backlight_vendor) {
+	if (acpi_video_handles_brightness_key_presses()) {
 		pr_info("This ThinkPad has standard ACPI backlight "
 			"brightness control, supported by the ACPI "
 			"video driver\n");