backlight: lp855x: Don't clear level on suspend/blank

Don't clear the backlight level when we're going into suspend or
blanking. Instead, just temporarily set the level to 0 so we retain
the value when we resume.
Reported-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Tested-by: Stephen Barber <smbarber@chromium.org>
Reviewed-by: Benson Leung <bleung@chromium.org>
Acked-by: Milo Kim <milo.kim@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/video/backlight/lp855x_bl.c

@@ -257,21 +257,15 @@ static void lp855x_pwm_ctrl(struct lp855x *lp, int br, int max_br)
 static int lp855x_bl_update_status(struct backlight_device *bl)
 {
 	struct lp855x *lp = bl_get_data(bl);
+	int brightness = bl->props.brightness;
 
 	if (bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
-		bl->props.brightness = 0;
+		brightness = 0;
 
-	if (lp->mode == PWM_BASED) {
-		int br = bl->props.brightness;
-		int max_br = bl->props.max_brightness;
-
-		lp855x_pwm_ctrl(lp, br, max_br);
-
-	} else if (lp->mode == REGISTER_BASED) {
-		u8 val = bl->props.brightness;
-
-		lp855x_write_byte(lp, lp->cfg->reg_brightness, val);
-	}
+	if (lp->mode == PWM_BASED)
+		lp855x_pwm_ctrl(lp, brightness, bl->props.max_brightness);
+	else if (lp->mode == REGISTER_BASED)
+		lp855x_write_byte(lp, lp->cfg->reg_brightness, (u8)brightness);
 
 	return 0;
 }