iio: adc: gyroadc: fix leak of device node iterator

Add missing of_node_put calls when exiting the for_each_child_of_node
loop in rcar_gyroadc_parse_subdevs early.

Also add goto-exception handling for the error paths in that loop.

Fixes: 059c53b3 ("iio: adc: Add Renesas GyroADC driver")
Signed-off-by: Tobias Jordan <kernel@cdqe.de>
Link: https://lore.kernel.org/r/20200926161946.GA10240@agrajag.zerfleddert.de
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/rcar-gyroadc.c

@@ -357,7 +357,7 @@ static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev)
 			num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_3);
 			break;
 		default:
-			return -EINVAL;
+			goto err_e_inval;
 		}
 
 		/*
@@ -374,7 +374,7 @@ static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev)
 				dev_err(dev,
 					"Failed to get child reg property of ADC \"%pOFn\".\n",
 					child);
-				return ret;
+				goto err_of_node_put;
 			}
 
 			/* Channel number is too high. */
@@ -382,7 +382,7 @@ static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev)
 				dev_err(dev,
 					"Only %i channels supported with %pOFn, but reg = <%i>.\n",
 					num_channels, child, reg);
-				return -EINVAL;
+				goto err_e_inval;
 			}
 		}
 
@@ -391,7 +391,7 @@ static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev)
 			dev_err(dev,
 				"Channel %i uses different ADC mode than the rest.\n",
 				reg);
-			return -EINVAL;
+			goto err_e_inval;
 		}
 
 		/* Channel is valid, grab the regulator. */
@@ -401,7 +401,8 @@ static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev)
 		if (IS_ERR(vref)) {
 			dev_dbg(dev, "Channel %i 'vref' supply not connected.\n",
 				reg);
-			return PTR_ERR(vref);
+			ret = PTR_ERR(vref);
+			goto err_of_node_put;
 		}
 
 		priv->vref[reg] = vref;
@@ -425,9 +426,11 @@ static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev)
 		 * attached to the GyroADC at a time, so if we found it,
 		 * we can stop parsing here.
 		 */
-		if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A)
+		if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) {
+			of_node_put(child);
 			break;
 		}
+	}
 
 	if (first) {
 		dev_err(dev, "No valid ADC channels found, aborting.\n");
@@ -435,6 +438,12 @@ static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev)
 	}
 
 	return 0;
+
+err_e_inval:
+	ret = -EINVAL;
+err_of_node_put:
+	of_node_put(child);
+	return ret;
 }
 
 static void rcar_gyroadc_deinit_supplies(struct iio_dev *indio_dev)