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: Carlos Corbacho <carlos@strangeworlds.co.uk>
Reported-by: Denis Mukhin <denis_mukhin@yahoo.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
index 07d14df..226b3e9 100644
--- a/drivers/platform/x86/acer-wmi.c
+++ b/drivers/platform/x86/acer-wmi.c
@@ -934,7 +934,7 @@
 	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;