powerpc/pci_dn: Add missing of_node_put()

In pci_add_device_node_info(), use of_node_put() to drop the reference
to 'parent' returned by of_get_parent() to keep refcount balance.

Fixes: cca87d30 ("powerpc/pci: Refactor pci_dn")
Co-authored-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/r/20220701131750.240170-1-windhl@126.com

arch/powerpc/kernel/pci_dn.c

@@ -330,6 +330,7 @@ struct pci_dn *pci_add_device_node_info(struct pci_controller *hose,
 	INIT_LIST_HEAD(&pdn->list);
 	parent = of_get_parent(dn);
 	pdn->parent = parent ? PCI_DN(parent) : NULL;
+	of_node_put(parent);
 	if (pdn->parent)
 		list_add_tail(&pdn->list, &pdn->parent->child_list);