dmaengine: mediatek: hsdma_probe: fixed a memory leak when devm_request_irq fails

When devm_request_irq fails, currently, the function
dma_async_device_unregister gets called. This doesn't free
the resources allocated by of_dma_controller_register.
Therefore, we have called of_dma_controller_free for this purpose.
Signed-off-by: Satendra Singh Thakur <sst2005@gmail.com>
Link: https://lore.kernel.org/r/20191109113523.6067-1-sst2005@gmail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/mediatek/mtk-hsdma.c

@@ -997,7 +997,7 @@ static int mtk_hsdma_probe(struct platform_device *pdev)
 	if (err) {
 		dev_err(&pdev->dev,
 			"request_irq failed with err %d\n", err);
-		goto err_unregister;
+		goto err_free;
 	}
 
 	platform_set_drvdata(pdev, hsdma);
@@ -1006,6 +1006,8 @@ static int mtk_hsdma_probe(struct platform_device *pdev)
 
 	return 0;
 
+err_free:
+	of_dma_controller_free(pdev->dev.of_node);
 err_unregister:
 	dma_async_device_unregister(dd);