ACPI / hotplug / PCI: Fix error code path in acpiphp_enumerate_slots()

One of the error code paths in acpiphp_enumerate_slots() is missing
a pci_dev_put(bridge->pci_dev) call, so add it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/hotplug/acpiphp_glue.c

@@ -1002,6 +1002,7 @@ void acpiphp_enumerate_slots(struct pci_bus *bus)
 		if (WARN_ON(!context)) {
 			mutex_unlock(&acpiphp_context_lock);
 			put_device(&bus->dev);
+			pci_dev_put(bridge->pci_dev);
 			kfree(bridge);
 			return;
 		}