ab8500-chargalg: Only root should have write permission on sysfs file

Only root should have write permission on sysfs file ab8500_chargalg/chargalg.

Cc: stable@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/power/abx500_chargalg.c

@@ -1711,7 +1711,7 @@ static ssize_t abx500_chargalg_sysfs_charger(struct kobject *kobj,
 static struct attribute abx500_chargalg_en_charger = \
 {
 	.name = "chargalg",
-	.mode = S_IWUGO,
+	.mode = S_IWUSR,
 };
 
 static struct attribute *abx500_chargalg_chg[] = {