mfd: Silence an lm3533 gcc warning

This is supposed to be umode_t.  It causes a GCC warning:
drivers/mfd/lm3533-core.c:440:2: warning: initialization from incompatible pointer type [enabled by default]
drivers/mfd/lm3533-core.c:440:2: warning: (near initialization for ‘lm3533_attribute_group.is_visible’) [enabled by default]
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/lm3533-core.c

@@ -359,7 +359,7 @@ static struct attribute *lm3533_attributes[] = {
 #define to_dev_attr(_attr) \
 	container_of(_attr, struct device_attribute, attr)
 
-static mode_t lm3533_attr_is_visible(struct kobject *kobj,
+static umode_t lm3533_attr_is_visible(struct kobject *kobj,
 					     struct attribute *attr, int n)
 {
 	struct device *dev = container_of(kobj, struct device, kobj);