PCI: allow PCI core hotplug to remove PCI root bus

There is no reason to prevent removal of root bus devices. A subsequent
rescan will find them just fine.
Reviewed-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/pci-sysfs.c

@@ -277,14 +277,10 @@ remove_store(struct device *dev, struct device_attribute *dummy,
 {
 	int ret = 0;
 	unsigned long val;
-	struct pci_dev *pdev = to_pci_dev(dev);
 
 	if (strict_strtoul(buf, 0, &val) < 0)
 		return -EINVAL;
 
-	if (pci_is_root_bus(pdev->bus))
-		return -EBUSY;
-
 	/* An attribute cannot be unregistered by one of its own methods,
 	 * so we have to use this roundabout approach.
 	 */