power_supply: 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: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

drivers/power/ab8500_btemp.c

@@ -938,7 +938,7 @@ static int ab8500_btemp_get_ext_psy_data(struct device *dev, void *data)
 		enum power_supply_property prop;
 		prop = ext->properties[j];
 
-		if (ext->get_property(ext, prop, &ret))
+		if (power_supply_get_property(ext, prop, &ret))
 			continue;
 
 		switch (prop) {

drivers/power/ab8500_charger.c

@@ -1957,7 +1957,7 @@ static int ab8500_charger_get_ext_psy_data(struct device *dev, void *data)
 		enum power_supply_property prop;
 		prop = ext->properties[j];
 
-		if (ext->get_property(ext, prop, &ret))
+		if (power_supply_get_property(ext, prop, &ret))
 			continue;
 
 		switch (prop) {

drivers/power/ab8500_fg.c

@@ -2200,7 +2200,7 @@ static int ab8500_fg_get_ext_psy_data(struct device *dev, void *data)
 		enum power_supply_property prop;
 		prop = ext->properties[j];
 
-		if (ext->get_property(ext, prop, &ret))
+		if (power_supply_get_property(ext, prop, &ret))
 			continue;
 
 		switch (prop) {

drivers/power/abx500_chargalg.c

@@ -1001,7 +1001,7 @@ static int abx500_chargalg_get_ext_psy_data(struct device *dev, void *data)
 	 * property because of handling that sysfs entry on its own, this is
 	 * the place to get the battery capacity.
 	 */
-	if (!ext->get_property(ext, POWER_SUPPLY_PROP_CAPACITY, &ret)) {
+	if (!power_supply_get_property(ext, POWER_SUPPLY_PROP_CAPACITY, &ret)) {
 		di->batt_data.percent = ret.intval;
 		capacity_updated = true;
 	}
@@ -1019,7 +1019,7 @@ static int abx500_chargalg_get_ext_psy_data(struct device *dev, void *data)
 			ext->type == POWER_SUPPLY_TYPE_USB)
 			di->usb_chg = psy_to_ux500_charger(ext);
 
-		if (ext->get_property(ext, prop, &ret))
+		if (power_supply_get_property(ext, prop, &ret))
 			continue;
 		switch (prop) {
 		case POWER_SUPPLY_PROP_PRESENT: