mfd: ab8500: Use power_supply_*() API for accessing function attrs

Replace direct calls to power supply function attributes with wrappers.
Wrappers provide safe access in case of unregistering the power
supply (e.g. by removing the driver). Replace:
 - get_property -> power_supply_get_property
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: NJonghwa Lee <jonghwa3.lee@samsung.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
Acked-by: NLee Jones <lee.jones@linaro.org>
Reviewed-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: NSebastian Reichel <sre@kernel.org>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

drivers/mfd/ab8500-sysctrl.c

@@ -49,7 +49,8 @@ static void ab8500_power_off(void)
 		if (!psy)
 			continue;
 
-		ret = psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &val);
+		ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_ONLINE,
+				&val);
 
 		if (!ret && val.intval) {
 			charger_present = true;
@@ -63,8 +64,8 @@ static void ab8500_power_off(void)
 	/* Check if battery is known */
 	psy = power_supply_get_by_name("ab8500_btemp");
 	if (psy) {
-		ret = psy->get_property(psy, POWER_SUPPLY_PROP_TECHNOLOGY,
-					&val);
+		ret = power_supply_get_property(psy,
+				POWER_SUPPLY_PROP_TECHNOLOGY, &val);
 		if (!ret && val.intval != POWER_SUPPLY_TECHNOLOGY_UNKNOWN) {
 			printk(KERN_INFO
 			       "Charger \"%s\" is connected with known battery."