qede: make driver reliable on unload after failures

In case recovery was not successful, netdev still should be
present. But we should clear cdev if something bad happens
on recovery.

We also check cdev for null on dev close. That could be a case
if recovery was not successful.
Signed-off-by: NIgor Russkikh <irusskikh@marvell.com>
Signed-off-by: NAlexander Lobakin <alobakin@marvell.com>
Signed-off-by: NMichal Kalderon <michal.kalderon@marvell.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/qlogic/qede/qede_main.c

@@ -1238,7 +1238,10 @@ static int __qede_probe(struct pci_dev *pdev, u32 dp_module, u8 dp_level,
 err4:
 	qede_rdma_dev_remove(edev, (mode == QEDE_PROBE_RECOVERY));
 err3:
-	free_netdev(edev->ndev);
+	if (mode != QEDE_PROBE_RECOVERY)
+		free_netdev(edev->ndev);
+	else
+		edev->cdev = NULL;
 err2:
 	qed_ops->common->slowpath_stop(cdev);
 err1:
@@ -2473,7 +2476,8 @@ static int qede_close(struct net_device *ndev)
 
 	qede_unload(edev, QEDE_UNLOAD_NORMAL, false);
 
-	edev->ops->common->update_drv_state(edev->cdev, false);
+	if (edev->cdev)
+		edev->ops->common->update_drv_state(edev->cdev, false);
 
 	return 0;
 }