samsung-laptop: cleanup return type: mode_t vs umode_t

This function returns a umode_t (unsigned short) instead of mode_t which
is an unsigned int on some architectures.  Cleaning this up silences a
compile warning:

drivers/platform/x86/samsung-laptop.c:1108:2: warning: initialization
	from incompatible pointer type [enabled by default]
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

drivers/platform/x86/samsung-laptop.c

@@ -1087,7 +1087,7 @@ static int __init samsung_backlight_init(struct samsung_laptop *samsung)
 	return 0;
 }
 
-static mode_t samsung_sysfs_is_visible(struct kobject *kobj,
+static umode_t samsung_sysfs_is_visible(struct kobject *kobj,
 				       struct attribute *attr, int idx)
 {
 	struct device *dev = container_of(kobj, struct device, kobj);