PCI: Convert alloc_pci_dev(void) to pci_alloc_dev(bus)

Use the new pci_alloc_dev(bus) to replace the existing using of
alloc_pci_dev(void).

[bhelgaas: drop pci_bus ref later in pci_release_dev()]
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: David Airlie <airlied@linux.ie>
Cc: Neela Syam Kolli <megaraidlinux@lsi.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index c93071d..2652ca0 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -75,18 +75,20 @@
 	struct pci_dev *virtfn;
 	struct resource *res;
 	struct pci_sriov *iov = dev->sriov;
+	struct pci_bus *bus;
 
-	virtfn = alloc_pci_dev();
+	virtfn = pci_alloc_dev(NULL);
 	if (!virtfn)
 		return -ENOMEM;
 
 	mutex_lock(&iov->dev->sriov->lock);
-	virtfn->bus = virtfn_add_bus(dev->bus, virtfn_bus(dev, id));
-	if (!virtfn->bus) {
+	bus = virtfn_add_bus(dev->bus, virtfn_bus(dev, id));
+	if (!bus) {
 		kfree(virtfn);
 		mutex_unlock(&iov->dev->sriov->lock);
 		return -ENOMEM;
 	}
+	virtfn->bus = pci_bus_get(bus);
 	virtfn->devfn = virtfn_devfn(dev, id);
 	virtfn->vendor = dev->vendor;
 	pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);