iio: adc: stm32-dfsdm: Use devm_platform_get_and_ioremap_resource()

Make use of devm_platform_get_and_ioremap_resource() provided by
driver core platform instead of duplicated analogue, dev_err() is
removed because it has been done in devm_ioremap_resource().
Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>
Link: https://lore.kernel.org/r/20200918083142.32816-1-bobo.shaobowang@huawei.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/stm32-dfsdm-core.c

@@ -226,16 +226,13 @@ static int stm32_dfsdm_parse_of(struct platform_device *pdev,
 	if (!node)
 		return -EINVAL;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res) {
-		dev_err(&pdev->dev, "Failed to get memory resource\n");
-		return -ENODEV;
-	}
-	priv->dfsdm.phys_base = res->start;
-	priv->dfsdm.base = devm_ioremap_resource(&pdev->dev, res);
+	priv->dfsdm.base = devm_platform_get_and_ioremap_resource(pdev, 0,
+							&res);
 	if (IS_ERR(priv->dfsdm.base))
 		return PTR_ERR(priv->dfsdm.base);
 
+	priv->dfsdm.phys_base = res->start;
+
 	/*
 	 * "dfsdm" clock is mandatory for DFSDM peripheral clocking.
 	 * "dfsdm" or "audio" clocks can be used as source clock for