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/bus.c b/drivers/pci/bus.c
index ba2bf55..447d393 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -235,7 +235,7 @@
  *
  * This adds add sysfs entries and start device drivers
  */
-int pci_bus_add_device(struct pci_dev *dev)
+void pci_bus_add_device(struct pci_dev *dev)
 {
 	int retval;
 
@@ -252,8 +252,6 @@
 	WARN_ON(retval < 0);
 
 	dev->is_added = 1;
-
-	return 0;
 }
 
 /**
@@ -266,16 +264,12 @@
 {
 	struct pci_dev *dev;
 	struct pci_bus *child;
-	int retval;
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		/* Skip already-added devices */
 		if (dev->is_added)
 			continue;
-		retval = pci_bus_add_device(dev);
-		if (retval)
-			dev_err(&dev->dev, "Error adding device (%d)\n",
-				retval);
+		pci_bus_add_device(dev);
 	}
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {