PCI: brcmstb: Fix missing of_node_put() in brcm_pcie_probe()

A call to of_parse_phandle() is incrementing the refcount, and as such,
the of_node_put() must be called when the reference is no longer needed.

Thus, refactor the existing code and add a missing of_node_put() call
following the check to ensure that "msi_np" matches "pcie->np" and after
MSI initialization, but only if the MSI support is enabled system-wide.

Cc: stable@vger.kernel.org # v5.10+
Fixes: 40ca1bf ("PCI: brcmstb: Add MSI support")
Signed-off-by: Stanimir Varbanov <svarbanov@suse.de>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20250122222955.1752778-1-svarbanov@suse.de
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>

drivers/pci/controller/pcie-brcmstb.c

@@ -1784,7 +1784,7 @@ static struct pci_ops brcm7425_pcie_ops = {
 
 static int brcm_pcie_probe(struct platform_device *pdev)
 {
-	struct device_node *np = pdev->dev.of_node, *msi_np;
+	struct device_node *np = pdev->dev.of_node;
 	struct pci_host_bridge *bridge;
 	const struct pcie_cfg_data *data;
 	struct brcm_pcie *pcie;
@@ -1888,9 +1888,14 @@ static int brcm_pcie_probe(struct platform_device *pdev)
 		goto fail;
 	}
 
-	msi_np = of_parse_phandle(pcie->np, "msi-parent", 0);
-	if (pci_msi_enabled() && msi_np == pcie->np) {
-		ret = brcm_pcie_enable_msi(pcie);
+	if (pci_msi_enabled()) {
+		struct device_node *msi_np = of_parse_phandle(pcie->np, "msi-parent", 0);
+
+		if (msi_np == pcie->np)
+			ret = brcm_pcie_enable_msi(pcie);
+
+		of_node_put(msi_np);
+
 		if (ret) {
 			dev_err(pcie->dev, "probe of internal MSI failed");
 			goto fail;