PCI: Leave normal LIST_POISON in deleted list entries

list_del() already sets next/prev to LIST_POISON1/LIST_POISON2, so we
don't need to do anything special here to prevent further list accesses.
Tested-by: NYijing Wang <wangyijing@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>

drivers/pci/remove.c

@@ -32,11 +32,8 @@ static void pci_stop_dev(struct pci_dev *dev)
 
 static void pci_destroy_dev(struct pci_dev *dev)
 {
-	/* Remove the device from the device lists, and prevent any further
-	 * list accesses from this device */
 	down_write(&pci_bus_sem);
 	list_del(&dev->bus_list);
-	dev->bus_list.next = dev->bus_list.prev = NULL;
 	up_write(&pci_bus_sem);
 
 	pci_free_resources(dev);