PCI: kirin: Convert kirin_pcie_parse_port() to scoped iterator

Convert loops in kirin_pcie_parse_port() to use the _scoped() version of
for_each_available_child_of_node() so the refcounts of children are
implicitly decremented when the loop is exited.

No functional change intended here, but it will make future error exits
from these loops easier.

Link: https://lore.kernel.org/linux-pci/20240609-pcie-kirin-memleak-v1-1-62b45b879576@gmail.com
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
[bhelgaas: move to GPIO series to avoid bisection hole, commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Author: javiercarrascocruz

drivers/pci/controller/dwc/pcie-kirin.c

@@ -400,11 +400,10 @@ static int kirin_pcie_parse_port(struct kirin_pcie *pcie,
 				 struct device_node *node)
 {
 	struct device *dev = &pdev->dev;
-	struct device_node *parent, *child;
 	int ret, slot, i;
 
-	for_each_available_child_of_node(node, parent) {
-		for_each_available_child_of_node(parent, child) {
+	for_each_available_child_of_node_scoped(node, parent) {
+		for_each_available_child_of_node_scoped(parent, child) {
 			i = pcie->num_slots;
 
 			pcie->gpio_id_reset[i] = of_get_named_gpio(child,
@@ -415,34 +414,26 @@ static int kirin_pcie_parse_port(struct kirin_pcie *pcie,
 			pcie->num_slots++;
 			if (pcie->num_slots > MAX_PCI_SLOTS) {
 				dev_err(dev, "Too many PCI slots!\n");
-				ret = -EINVAL;
-				goto put_node;
+				return -EINVAL;
 			}
 
 			ret = of_pci_get_devfn(child);
 			if (ret < 0) {
 				dev_err(dev, "failed to parse devfn: %d\n", ret);
-				goto put_node;
+				return ret;
 			}
 
 			slot = PCI_SLOT(ret);
 
 			pcie->reset_names[i] = devm_kasprintf(dev, GFP_KERNEL,
 							      "pcie_perst_%d",
 							      slot);
-			if (!pcie->reset_names[i]) {
-				ret = -ENOMEM;
-				goto put_node;
-			}
+			if (!pcie->reset_names[i])
+				return -ENOMEM;
 		}
 	}
 
 	return 0;
-
-put_node:
-	of_node_put(child);
-	of_node_put(parent);
-	return ret;
 }
 
 static long kirin_pcie_get_resource(struct kirin_pcie *kirin_pcie,