igb: fix EEH recovery during reset on PPC

EEH is not recovering in a reasonable amount of time on PPC during
igb_down().
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

drivers/net/igb/igb_main.c

@@ -718,7 +718,8 @@ void igb_down(struct igb_adapter *adapter)
 	adapter->link_speed = 0;
 	adapter->link_duplex = 0;
 
-	igb_reset(adapter);
+	if (!pci_channel_offline(adapter->pdev))
+		igb_reset(adapter);
 	igb_clean_all_tx_rings(adapter);
 	igb_clean_all_rx_rings(adapter);
 }