cxl: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/add08320eef9ea20ceca78648370590a4bd447b0.1708508896.git.u.kleine-koenig@pengutronix.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/cxl/of.c

@@ -431,7 +431,7 @@ int cxl_of_read_adapter_properties(struct cxl *adapter, struct device_node *np)
 	return 0;
 }
 
-static int cxl_of_remove(struct platform_device *pdev)
+static void cxl_of_remove(struct platform_device *pdev)
 {
 	struct cxl *adapter;
 	int afu;
@@ -441,7 +441,6 @@ static int cxl_of_remove(struct platform_device *pdev)
 		cxl_guest_remove_afu(adapter->afu[afu]);
 
 	cxl_guest_remove_adapter(adapter);
-	return 0;
 }
 
 static void cxl_of_shutdown(struct platform_device *pdev)
@@ -501,6 +500,6 @@ struct platform_driver cxl_of_driver = {
 		.owner = THIS_MODULE
 	},
 	.probe = cxl_of_probe,
-	.remove = cxl_of_remove,
+	.remove_new = cxl_of_remove,
 	.shutdown = cxl_of_shutdown,
 };