acer-wmi: Respect current backlight level when loading

Set the backlight to use the current brightness when loaded, rather than
always resetting the backlight to maximum brightness.

Fixes kernel bugzilla #14207
Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Reported-by: NDenis Mukhin <denis_mukhin@yahoo.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

drivers/platform/x86/acer-wmi.c

@@ -934,7 +934,7 @@ static int __devinit acer_backlight_init(struct device *dev)
 	acer_backlight_device = bd;
 
 	bd->props.power = FB_BLANK_UNBLANK;
-	bd->props.brightness = max_brightness;
+	bd->props.brightness = read_brightness(bd);
 	bd->props.max_brightness = max_brightness;
 	backlight_update_status(bd);
 	return 0;