igbvf: return PCI_ERS_RESULT_DISCONNECT on permanent failure

PCI drivers that implement the struct pci_error_handlers' error_detected
callback should return PCI_ERS_RESULT_DISCONNECT if the state passed in is
pci_channel_io_perm_failure. This patch fixes the issue for igbvf.

Signed-off-by: Dean Nelson <dnelson@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/igbvf/netdev.c b/drivers/net/igbvf/netdev.c
index 926c31b..3f03c42 100644
--- a/drivers/net/igbvf/netdev.c
+++ b/drivers/net/igbvf/netdev.c
@@ -2511,6 +2511,9 @@
 
 	netif_device_detach(netdev);
 
+	if (state == pci_channel_io_perm_failure)
+		return PCI_ERS_RESULT_DISCONNECT;
+
 	if (netif_running(netdev))
 		igbvf_down(adapter);
 	pci_disable_device(pdev);