sparc/vio: make remove callback return void

The driver core ignores the return value of struct bus_type::remove()
because there is only little that can be done. To simplify the quest to
make this function return void, let struct vio_driver::remove() return
void, too. All users already unconditionally return 0, this commit makes
it obvious that returning an error code is a bad idea and should prevent
that future driver authors consider returning an error code.

Note there are two nominally different implementations for a vio bus:
one in arch/sparc/kernel/vio.c and the other in
arch/powerpc/platforms/pseries/vio.c. This patch only addresses the
former.

Acked-by: David S. Miller <[e-mail]>
Signed-off-by: Uwe Kleine-König <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

arch/sparc/include/asm/vio.h

···
 	struct list_head		node;
 	const struct vio_device_id	*id_table;
 	int (*probe)(struct vio_dev *dev, const struct vio_device_id *id);
-	int (*remove)(struct vio_dev *dev);
+	void (*remove)(struct vio_dev *dev);
 	void (*shutdown)(struct vio_dev *dev);
 	unsigned long			driver_data;
 	struct device_driver		driver;

arch/sparc/kernel/ds.c

···
 	return err;
 }
 
-static int ds_remove(struct vio_dev *vdev)
-{
-	return 0;
-}
-
 static const struct vio_device_id ds_match[] = {
 	{
 		.type = "domain-services-port",
···
 static struct vio_driver ds_driver = {
 	.id_table	= ds_match,
 	.probe		= ds_probe,
-	.remove		= ds_remove,
 	.name		= "ds",
 };
 

arch/sparc/kernel/vio.c

···
 		 * routines to do so at the moment. TBD
 		 */
 
-		return drv->remove(vdev);
+		drv->remove(vdev);
 	}
 
-	return 1;
+	return 0;
 }
 
 static ssize_t devspec_show(struct device *dev,

drivers/block/sunvdc.c

···
 	return err;
 }
 
-static int vdc_port_remove(struct vio_dev *vdev)
+static void vdc_port_remove(struct vio_dev *vdev)
 {
 	struct vdc_port *port = dev_get_drvdata(&vdev->dev);
 
···
 
 		kfree(port);
 	}
-	return 0;
 }
 
 static void vdc_requeue_inflight(struct vdc_port *port)

drivers/net/ethernet/sun/ldmvsw.c

···
 	return err;
 }
 
-static int vsw_port_remove(struct vio_dev *vdev)
+static void vsw_port_remove(struct vio_dev *vdev)
 {
 	struct vnet_port *port = dev_get_drvdata(&vdev->dev);
 	unsigned long flags;
···
 
 		free_netdev(port->dev);
 	}
-
-	return 0;
 }
 
 static void vsw_cleanup(void)

drivers/net/ethernet/sun/sunvnet.c

···
 	return err;
 }
 
-static int vnet_port_remove(struct vio_dev *vdev)
+static void vnet_port_remove(struct vio_dev *vdev)
 {
 	struct vnet_port *port = dev_get_drvdata(&vdev->dev);
 
···
 
 		kfree(port);
 	}
-	return 0;
 }
 
 static const struct vio_device_id vnet_port_match[] = {

drivers/tty/vcc.c

···
  *
  * Return: status of removal
  */
-static int vcc_remove(struct vio_dev *vdev)
+static void vcc_remove(struct vio_dev *vdev)
 {
 	struct vcc_port *port = dev_get_drvdata(&vdev->dev);
 
···
 		kfree(port->domain);
 		kfree(port);
 	}
-
-	return 0;
 }
 
 static const struct vio_device_id vcc_match[] = {