igbvf: fix the bug when initializing the igbvf

Maybe it's a typo, but it cause that igbvf can't be initialized successfully.
Set perm_addr value using valid dev_addr, although which is equal to hw.mac.addr.
Signed-off-by: Samuel Liao <samuelliao@tencent.com>
Signed-off-by: Shan Wei <davidshan@tencent.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/igbvf/netdev.c

@@ -2731,14 +2731,14 @@ static int __devinit igbvf_probe(struct pci_dev *pdev,
 			netdev->addr_len);
 	}
 
-	if (!is_valid_ether_addr(netdev->perm_addr)) {
+	if (!is_valid_ether_addr(netdev->dev_addr)) {
 		dev_err(&pdev->dev, "Invalid MAC Address: %pM\n",
 		        netdev->dev_addr);
 		err = -EIO;
 		goto err_hw_init;
 	}
 
-	memcpy(netdev->perm_addr, adapter->hw.mac.addr, netdev->addr_len);
+	memcpy(netdev->perm_addr, netdev->dev_addr, netdev->addr_len);
 
 	setup_timer(&adapter->watchdog_timer, &igbvf_watchdog,
 	            (unsigned long) adapter);