dmaengine: mmp_pdma: 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() is 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>
Link: https://lore.kernel.org/r/20230919133207.1400430-26-u.kleine-koenig@pengutronix.deSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/mmp_pdma.c

@@ -932,7 +932,7 @@ static void dma_do_tasklet(struct tasklet_struct *t)
 	}
 }
 
-static int mmp_pdma_remove(struct platform_device *op)
+static void mmp_pdma_remove(struct platform_device *op)
 {
 	struct mmp_pdma_device *pdev = platform_get_drvdata(op);
 	struct mmp_pdma_phy *phy;
@@ -958,7 +958,6 @@ static int mmp_pdma_remove(struct platform_device *op)
 	}
 
 	dma_async_device_unregister(&pdev->device);
-	return 0;
 }
 
 static int mmp_pdma_chan_init(struct mmp_pdma_device *pdev, int idx, int irq)
@@ -1141,7 +1140,7 @@ static struct platform_driver mmp_pdma_driver = {
 	},
 	.id_table	= mmp_pdma_id_table,
 	.probe		= mmp_pdma_probe,
-	.remove		= mmp_pdma_remove,
+	.remove_new	= mmp_pdma_remove,
 };
 
 module_platform_driver(mmp_pdma_driver);