PCI/pwrctrl: Fix device and OF node leak at bus scan

Make sure to drop the references to the pwrctrl OF node and device taken by
of_pci_find_child_device() and of_find_device_by_node() respectively when
scanning the bus.

Fixes: 957f40d ("PCI/pwrctrl: Move creation of pwrctrl devices to pci_scan_device()")
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Cc: stable@vger.kernel.org	# v6.15
Link: https://patch.msgid.link/20250721153609.8611-3-johan+linaro@kernel.org

Author: jhovold

drivers/pci/probe.c

@@ -2516,27 +2516,40 @@ static struct platform_device *pci_pwrctrl_create_device(struct pci_bus *bus, in
 	struct device_node *np;
 
 	np = of_pci_find_child_device(dev_of_node(&bus->dev), devfn);
-	if (!np || of_find_device_by_node(np))
+	if (!np)
 		return NULL;
 
+	pdev = of_find_device_by_node(np);
+	if (pdev) {
+		put_device(&pdev->dev);
+		goto err_put_of_node;
+	}
+
 	/*
 	 * First check whether the pwrctrl device really needs to be created or
 	 * not. This is decided based on at least one of the power supplies
 	 * being defined in the devicetree node of the device.
 	 */
 	if (!of_pci_supply_present(np)) {
 		pr_debug("PCI/pwrctrl: Skipping OF node: %s\n", np->name);
-		return NULL;
+		goto err_put_of_node;
 	}
 
 	/* Now create the pwrctrl device */
 	pdev = of_platform_device_create(np, NULL, &host->dev);
 	if (!pdev) {
 		pr_err("PCI/pwrctrl: Failed to create pwrctrl device for node: %s\n", np->name);
-		return NULL;
+		goto err_put_of_node;
 	}
 
+	of_node_put(np);
+
 	return pdev;
+
+err_put_of_node:
+	of_node_put(np);
+
+	return NULL;
 }
 #else
 static struct platform_device *pci_pwrctrl_create_device(struct pci_bus *bus, int devfn)