iio: adc: stm32-dfsdm: manage the get_irq error case

During probe, check the "get_irq" error value.
Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

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

@@ -1456,6 +1456,12 @@ static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
 	 * So IRQ associated to filter instance 0 is dedicated to the Filter 0.
 	 */
 	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		if (irq != -EPROBE_DEFER)
+			dev_err(dev, "Failed to get IRQ: %d\n", irq);
+		return irq;
+	}
+
 	ret = devm_request_irq(dev, irq, stm32_dfsdm_irq,
 			       0, pdev->name, adc);
 	if (ret < 0) {