[ACPI] acpi_video_device_write_state() now works

http://bugzilla.kernel.org/show_bug.cgi?id=5060

Signed-off-by: Luming Yu <luming.yu@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/video.c

@@ -297,11 +297,12 @@ acpi_video_device_set_state(struct acpi_video_device *device, int state)
 	int status;
 	union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 	struct acpi_object_list args = { 1, &arg0 };
+	unsigned long ret;
 
 	ACPI_FUNCTION_TRACE("acpi_video_device_set_state");
 
 	arg0.integer.value = state;
-	status = acpi_evaluate_integer(device->handle, "_DSS", &args, NULL);
+	status = acpi_evaluate_integer(device->handle, "_DSS", &args, &ret);
 
 	return_VALUE(status);
 }