power_supply: Fix regression for 'type' property

Commit 5f487cd34f (power_supply: Use
attribute groups) causes a regression the power supply core does not
export the 'type' attribute anymore.

POWER_SUPPLY_PROP_TYPE is handled by the power supply core without the
low-level driver, so power_supply_attr_is_visible() must always return
the entry as readable.

Reported-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

drivers/power/power_supply_sysfs.c

@@ -179,14 +179,16 @@ static mode_t power_supply_attr_is_visible(struct kobject *kobj,
 {
 	struct device *dev = container_of(kobj, struct device, kobj);
 	struct power_supply *psy = dev_get_drvdata(dev);
+	mode_t mode = S_IRUSR | S_IRGRP | S_IROTH;
 	int i;
 
+	if (attrno == POWER_SUPPLY_PROP_TYPE)
+		return mode;
+
 	for (i = 0; i < psy->num_properties; i++) {
 		int property = psy->properties[i];
 
 		if (property == attrno) {
-			mode_t mode = S_IRUSR | S_IRGRP | S_IROTH;
-
 			if (psy->property_is_writeable &&
 			    psy->property_is_writeable(psy, property) > 0)
 				mode |= S_IWUSR;