PCI: mt7621: Use helper function for_each_available_child_of_node_scoped()

The for_each_available_child_of_node_scoped() helper provides
a scope-based clean-up functionality to put the device_node
automatically, and as such, there is no need to call of_node_put()
directly.

Thus, use this helper to simplify the code.

Signed-off-by: Zhang Zekun <zhangzekun11@huawei.com>
Reviewed-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20240831040413.126417-5-zhangzekun11@huawei.com
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>

Author: Zhang Zekun

drivers/pci/controller/pcie-mt7621.c

@@ -258,30 +258,25 @@ static int mt7621_pcie_parse_dt(struct mt7621_pcie *pcie)
 {
 	struct device *dev = pcie->dev;
 	struct platform_device *pdev = to_platform_device(dev);
-	struct device_node *node = dev->of_node, *child;
+	struct device_node *node = dev->of_node;
 	int err;
 
 	pcie->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(pcie->base))
 		return PTR_ERR(pcie->base);
 
-	for_each_available_child_of_node(node, child) {
+	for_each_available_child_of_node_scoped(node, child) {
 		int slot;
 
 		err = of_pci_get_devfn(child);
-		if (err < 0) {
-			of_node_put(child);
-			dev_err(dev, "failed to parse devfn: %d\n", err);
-			return err;
-		}
+		if (err < 0)
+			return dev_err_probe(dev, err, "failed to parse devfn\n");
 
 		slot = PCI_SLOT(err);
 
 		err = mt7621_pcie_parse_port(pcie, child, slot);
-		if (err) {
-			of_node_put(child);
+		if (err)
 			return err;
-		}
 	}
 
 	return 0;