iio: adc: rockchip_saradc: add NULL check on of_match_device() return value

Check return value from call to of_match_device()
in order to prevent a NULL pointer dereference.

In case of NULL print error message and return -ENODEV
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/rockchip_saradc.c

@@ -224,6 +224,11 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
 	info = iio_priv(indio_dev);
 
 	match = of_match_device(rockchip_saradc_match, &pdev->dev);
+	if (!match) {
+		dev_err(&pdev->dev, "failed to match device\n");
+		return -ENODEV;
+	}
+
 	info->data = match->data;
 
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);