video: fbdev: Fix format string mismatch in wm8505fb.c

Fix format string mismatch in contrast_show().
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/fbdev/wm8505fb.c

@@ -162,7 +162,7 @@ static ssize_t contrast_show(struct device *dev,
 	struct fb_info *info = dev_get_drvdata(dev);
 	struct wm8505fb_info *fbi = to_wm8505fb_info(info);
 
-	return sprintf(buf, "%d\n", fbi->contrast);
+	return sprintf(buf, "%u\n", fbi->contrast);
 }
 
 static ssize_t contrast_store(struct device *dev,