igb: save and restore pcie/msi state to support EEH recovery

To enable EEH support for pci-express network adapters, pcie/msi state
needs to be saved and restored for that adapter.

[after similar patches for ixgbe and e1000e from Wendy Xiong]

Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
Cc: Wendy Xiong <wendyx@us.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/net/igb/igb_main.c

diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index aaee02e..ae398f0 100644
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -871,6 +871,7 @@
 		goto err_pci_reg;
 
 	pci_set_master(pdev);
+	pci_save_state(pdev);
 
 	err = -ENOMEM;
 	netdev = alloc_etherdev(sizeof(struct igb_adapter));
@@ -4079,6 +4080,7 @@
 		return PCI_ERS_RESULT_DISCONNECT;
 	}
 	pci_set_master(pdev);
+	pci_restore_state(pdev);
 
 	pci_enable_wake(pdev, PCI_D3hot, 0);
 	pci_enable_wake(pdev, PCI_D3cold, 0);