PCI: Make device create/destroy logic symmetric

According to device model documentation, the way to create/destroy PCI
devices should be symmetric.  The rule is to either use
  1) device_register()/device_unregister()
or
  2) device_initialize()/device_add()/device_del()/put_device().

So change PCI core logic to follow the rule and get rid of the redundant
pci_dev_get()/pci_dev_put() pair.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
index 7c0fd92..fc38c48 100644
--- a/drivers/pci/remove.c
+++ b/drivers/pci/remove.c
@@ -22,7 +22,7 @@
 	if (dev->is_added) {
 		pci_proc_detach_device(dev);
 		pci_remove_sysfs_dev_files(dev);
-		device_unregister(&dev->dev);
+		device_del(&dev->dev);
 		dev->is_added = 0;
 	}
 
@@ -37,7 +37,7 @@
 	up_write(&pci_bus_sem);
 
 	pci_free_resources(dev);
-	pci_dev_put(dev);
+	put_device(&dev->dev);
 }
 
 void pci_remove_bus(struct pci_bus *bus)