video: replace strict_strtoul() with kstrtoul()

The usage of strict_strtoul() is not preferred, because
strict_strtoul() is obsolete. Thus, kstrtoul() should be
used.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/wm8505fb.c b/drivers/video/wm8505fb.c
index 01f9ace..3072f30 100644
--- a/drivers/video/wm8505fb.c
+++ b/drivers/video/wm8505fb.c
@@ -173,7 +173,7 @@
 	struct wm8505fb_info *fbi = to_wm8505fb_info(info);
 	unsigned long tmp;
 
-	if (strict_strtoul(buf, 10, &tmp) || (tmp > 0xff))
+	if (kstrtoul(buf, 10, &tmp) || (tmp > 0xff))
 		return -EINVAL;
 	fbi->contrast = tmp;