ACPI: video: Drop backlight_device_get_by_type() call from acpi_video_get_backlight_type()

All x86/ACPI kms drivers which register native/BACKLIGHT_RAW type
backlight devices call acpi_video_backlight_use_native() now. This sets
__acpi_video_get_backlight_type()'s internal static native_available flag.

This makes the backlight_device_get_by_type(BACKLIGHT_RAW) check
unnecessary.

Relying on the cached native_available value not only is simpler, it will
also work correctly in cases where then native backlight registration was
skipped because of acpi_video_backlight_use_native() returning false.
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/acpi/video_detect.c

@@ -608,8 +608,7 @@ static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native)
 	if (!(video_caps & ACPI_VIDEO_BACKLIGHT))
 		return acpi_backlight_vendor;
 
-	if (acpi_osi_is_win8() &&
-	    (native_available || backlight_device_get_by_type(BACKLIGHT_RAW)))
+	if (acpi_osi_is_win8() && native_available)
 		return acpi_backlight_native;
 
 	return acpi_backlight_video;