igb: return PCI_ERS_RESULT_DISCONNECT on permanent error

PCI drivers that implement the io_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 igb.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/igb/igb_main.c

@@ -5339,6 +5339,9 @@ static pci_ers_result_t igb_io_error_detected(struct pci_dev *pdev,
 
 	netif_device_detach(netdev);
 
+	if (state == pci_channel_io_perm_failure)
+		return PCI_ERS_RESULT_DISCONNECT;
+
 	if (netif_running(netdev))
 		igb_down(adapter);
 	pci_disable_device(pdev);