dmaengine: axi-dmac: add a check for devm_regmap_init_mmio

The driver misses checking the result of devm_regmap_init_mmio().
Add a check to fix it.

Fixes: fc15be3 ("dmaengine: axi-dmac: add regmap support")
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20191209085711.16001-1-hslester96@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/dma-axi-dmac.c

@@ -830,6 +830,7 @@ static int axi_dmac_probe(struct platform_device *pdev)
 	struct dma_device *dma_dev;
 	struct axi_dmac *dmac;
 	struct resource *res;
+	struct regmap *regmap;
 	int ret;
 
 	dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL);
@@ -921,10 +922,17 @@ static int axi_dmac_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, dmac);
 
-	devm_regmap_init_mmio(&pdev->dev, dmac->base, &axi_dmac_regmap_config);
+	regmap = devm_regmap_init_mmio(&pdev->dev, dmac->base,
+		 &axi_dmac_regmap_config);
+	if (IS_ERR(regmap)) {
+		ret = PTR_ERR(regmap);
+		goto err_free_irq;
+	}
 
 	return 0;
 
+err_free_irq:
+	free_irq(dmac->irq, dmac);
 err_unregister_of:
 	of_dma_controller_free(pdev->dev.of_node);
 err_unregister_device: