ACPI battery: don't invoke power_supply_changed twice when battery is hot-added

When battery is hot-added, we should not invoke power_supply_changed
in acpi_battery_notify, because it has been invoked in acpi_battery_update,
and battery->bat.changed_work is queued in keventd already.
https://bugzilla.kernel.org/show_bug.cgi?id=16244

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Alexey Starikovskiy <astarikovskiy@sude.de>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/battery.c

@@ -868,9 +868,15 @@ static void acpi_battery_remove_fs(struct acpi_device *device)
 static void acpi_battery_notify(struct acpi_device *device, u32 event)
 {
 	struct acpi_battery *battery = acpi_driver_data(device);
+#ifdef CONFIG_ACPI_SYSFS_POWER
+	struct device *old;
+#endif
 
 	if (!battery)
 		return;
+#ifdef CONFIG_ACPI_SYSFS_POWER
+	old = battery->bat.dev;
+#endif
 	acpi_battery_update(battery);
 	acpi_bus_generate_proc_event(device, event,
 				     acpi_battery_present(battery));
@@ -879,7 +885,7 @@ static void acpi_battery_notify(struct acpi_device *device, u32 event)
 					acpi_battery_present(battery));
 #ifdef CONFIG_ACPI_SYSFS_POWER
 	/* acpi_battery_update could remove power_supply object */
-	if (battery->bat.dev)
+	if (old && battery->bat.dev)
 		power_supply_changed(&battery->bat);
 #endif
 }