PCI: Fix sriov_enable() error path for pcibios_enable_sriov() failures

Disable VFs if pcibios_enable_sriov() fails, just like we do for other
errors in sriov_enable().  Call pcibios_sriov_disable() if virtfn_add()
fails.

[bhelgaas: changelog, split to separate patch for reviewability]
Fixes: 995df527 ("PCI: Add pcibios_sriov_enable() and pcibios_sriov_disable()")
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Wei Yang <weiyang@linux.vnet.ibm.com>

drivers/pci/iov.c

@@ -246,7 +246,6 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 	struct pci_sriov *iov = dev->sriov;
 	int bars = 0;
 	int bus;
-	int retval;
 
 	if (!nr_virtfn)
 		return 0;
@@ -315,10 +314,10 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 	if (nr_virtfn < initial)
 		initial = nr_virtfn;
 
-	if ((retval = pcibios_sriov_enable(dev, initial))) {
-		dev_err(&dev->dev, "failure %d from pcibios_sriov_enable()\n",
-			retval);
-		return retval;
+	rc = pcibios_sriov_enable(dev, initial);
+	if (rc) {
+		dev_err(&dev->dev, "failure %d from pcibios_sriov_enable()\n", rc);
+		goto err_pcibios;
 	}
 
 	for (i = 0; i < initial; i++) {
@@ -336,6 +335,8 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 	while (i--)
 		virtfn_remove(dev, i, 0);
 
+	pcibios_sriov_disable(dev);
+err_pcibios:
 	iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
 	pci_cfg_access_lock(dev);
 	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);