PCI: uniphier: Fix a leaked reference by adding missing of_node_put()

The call to of_get_child_by_name() returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.

irq_domain_add_linear() also calls of_node_get() to increase refcount,
so irq_domain will not be affected when it is released.

Detected by coccinelle with the following warnings:
  ./drivers/pci/controller/dwc/pcie-uniphier.c:283:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 274, but without a corresponding object release within this function.
  ./drivers/pci/controller/dwc/pcie-uniphier.c:290:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 274, but without a corresponding object release within this function.
  ./drivers/pci/controller/dwc/pcie-uniphier.c:296:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 274, but without a corresponding object release within this function.

Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org

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

@@ -270,6 +270,7 @@ static int uniphier_pcie_config_legacy_irq(struct pcie_port *pp)
 	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
 	struct device_node *np = pci->dev->of_node;
 	struct device_node *np_intc;
+	int ret = 0;
 
 	np_intc = of_get_child_by_name(np, "legacy-interrupt-controller");
 	if (!np_intc) {
@@ -280,20 +281,24 @@ static int uniphier_pcie_config_legacy_irq(struct pcie_port *pp)
 	pp->irq = irq_of_parse_and_map(np_intc, 0);
 	if (!pp->irq) {
 		dev_err(pci->dev, "Failed to get an IRQ entry in legacy-interrupt-controller\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out_put_node;
 	}
 
 	priv->legacy_irq_domain = irq_domain_add_linear(np_intc, PCI_NUM_INTX,
 						&uniphier_intx_domain_ops, pp);
 	if (!priv->legacy_irq_domain) {
 		dev_err(pci->dev, "Failed to get INTx domain\n");
-		return -ENODEV;
+		ret = -ENODEV;
+		goto out_put_node;
 	}
 
 	irq_set_chained_handler_and_data(pp->irq, uniphier_pcie_irq_handler,
 					 pp);
 
-	return 0;
+out_put_node:
+	of_node_put(np_intc);
+	return ret;
 }
 
 static int uniphier_pcie_host_init(struct pcie_port *pp)