mfd: update workqueue usages

flush_scheduled_work() is deprecated and scheduled to be removed.

* In menelaus, flush menelaus->work directly on probe failure.  Also,
  make sure the work isn't running on removal.

* In tps65010, cancel_delayed_work() + flush_scheduled_work() ->
  cancel_delayed_work_sync().  While at it, remove unnecessary (void)
  casts on return value, and use schedule_delayed_work() and
  to_delayed_work() instead of using delayed_work's internal work
  field.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/menelaus.c

@@ -1259,7 +1259,7 @@ static int menelaus_probe(struct i2c_client *client,
 	return 0;
 fail2:
 	free_irq(client->irq, menelaus);
-	flush_scheduled_work();
+	flush_work_sync(&menelaus->work);
 fail1:
 	kfree(menelaus);
 	return err;
@@ -1270,6 +1270,7 @@ static int __exit menelaus_remove(struct i2c_client *client)
 	struct menelaus_chip	*menelaus = i2c_get_clientdata(client);
 
 	free_irq(client->irq, menelaus);
+	flush_work_sync(&menelaus->work);
 	kfree(menelaus);
 	the_menelaus = NULL;
 	return 0;