iio: adc: rcar-gyroadc: use for_each_available_child_node_scoped()

Using automated cleanup to replace of_node_put() handling allows for
a simplfied flow by enabling direct returns on errors.

Non available child nodes should never have been considered; that
is ones where status != okay and was defined.
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20240225142714.286440-5-jic23@kernel.orgSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/rcar-gyroadc.c

@@ -318,7 +318,6 @@ static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev)
 	struct rcar_gyroadc *priv = iio_priv(indio_dev);
 	struct device *dev = priv->dev;
 	struct device_node *np = dev->of_node;
-	struct device_node *child;
 	struct regulator *vref;
 	unsigned int reg;
 	unsigned int adcmode = -1, childmode;
@@ -326,7 +325,7 @@ static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev)
 	unsigned int num_channels;
 	int ret, first = 1;
 
-	for_each_child_of_node(np, child) {
+	for_each_available_child_of_node_scoped(np, child) {
 		of_id = of_match_node(rcar_gyroadc_child_match, child);
 		if (!of_id) {
 			dev_err(dev, "Ignoring unsupported ADC \"%pOFn\".",
@@ -352,7 +351,7 @@ static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev)
 			num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_3);
 			break;
 		default:
-			goto err_e_inval;
+			return -EINVAL;
 		}
 
 		/*
@@ -369,7 +368,7 @@ 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);
-				goto err_of_node_put;
+				return ret;
 			}
 
 			/* Channel number is too high. */
@@ -377,7 +376,7 @@ 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);
-				goto err_e_inval;
+				return -EINVAL;
 			}
 		}
 
@@ -386,7 +385,7 @@ 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);
-			goto err_e_inval;
+			return -EINVAL;
 		}
 
 		/* Channel is valid, grab the regulator. */
@@ -396,8 +395,7 @@ 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);
-			ret = PTR_ERR(vref);
-			goto err_of_node_put;
+			return PTR_ERR(vref);
 		}
 
 		priv->vref[reg] = vref;
@@ -422,7 +420,6 @@ static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev)
 		 * we can stop parsing here.
 		 */
 		if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) {
-			of_node_put(child);
 			break;
 		}
 	}
@@ -433,12 +430,6 @@ 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)