PCI: Remove unused "rc" in virtfn_add_bus()

Delete unused variable "rc" to fix build warning in drivers/pci/iov.c
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/iov.c

@@ -33,7 +33,6 @@ static inline u8 virtfn_devfn(struct pci_dev *dev, int id)
 
 static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
 {
-	int rc;
 	struct pci_bus *child;
 
 	if (bus->number == busnr)