backlight: pcf50633: Add blank line after declarations

Fixed the following checkpatch warning.

  WARNING: Missing a blank line after declarations
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/video/backlight/pcf50633-backlight.c

@@ -90,6 +90,7 @@ static int pcf50633_bl_update_status(struct backlight_device *bl)
 static int pcf50633_bl_get_brightness(struct backlight_device *bl)
 {
 	struct pcf50633_bl *pcf_bl = bl_get_data(bl);
+
 	return pcf_bl->brightness;
 }