auxdisplay: ht16k33: Replace use of fb_blank with backlight helper

Replace the use of struct backlight_properties.fb_blank with a call
to backlight_get_brightness(). The helper implements similar logic
as the driver's function. It also accounts for BL_CORE_SUSPENDED for
drivers that set BL_CORE_SUSPENDRESUME. Ht16k33 doesn't use this, so
there's no change in behaviour here.

Signed-off-by: Thomas Zimmermann <[e-mail]>
Cc: Robin van der Gracht <[e-mail]>
Cc: Miguel Ojeda <[e-mail]>
Reviewed-by: Sam Ravnborg <[e-mail]>
Reviewed-by: Geert Uytterhoeven <[e-mail]>
Reviewed-by: Miguel Ojeda <[e-mail]>
Reviewed-by: Robin van der Gracht <[e-mail]>
Reviewed-by: Dan Carpenter <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Lee Jones <[e-mail]>

drivers/auxdisplay/ht16k33.c

···
 
 static int ht16k33_bl_update_status(struct backlight_device *bl)
 {
-	int brightness = bl->props.brightness;
+	const int brightness = backlight_get_brightness(bl);
 	struct ht16k33_priv *priv = bl_get_data(bl);
-
-	if (bl->props.power != FB_BLANK_UNBLANK ||
-	    bl->props.fb_blank != FB_BLANK_UNBLANK ||
-	    bl->props.state & BL_CORE_FBBLANK)
-		brightness = 0;
 
 	return ht16k33_brightness_set(priv, brightness);
 }