PCI: Make pci_bus_add_device() void

pci_bus_add_device() always returns 0, so there's no point in returning
anything at all.  Make it a void function and remove the tests of the
return value from the callers.

[bhelgaas: changelog, remove unused "err" from i82875p_setup_overfl_dev()]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index de7a747..cb6f247 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -106,7 +106,7 @@
 	pci_device_add(virtfn, virtfn->bus);
 	mutex_unlock(&iov->dev->sriov->lock);
 
-	rc = pci_bus_add_device(virtfn);
+	pci_bus_add_device(virtfn);
 	sprintf(buf, "virtfn%u", id);
 	rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
 	if (rc)