power_supply: Don't use flush_scheduled_work()

flush_scheduled_work() is deprecated and scheduled to be removed.

In battery drivers, the work can be canceled on probe failure and
removal and should be flushed on suspend.  Replace
flush_scheduled_work() usages with direct cancels and flushes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index f06bad0..970f733 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -201,7 +201,7 @@
 
 void power_supply_unregister(struct power_supply *psy)
 {
-	flush_scheduled_work();
+	cancel_work_sync(&psy->changed_work);
 	power_supply_remove_triggers(psy);
 	device_unregister(psy->dev);
 }