net: qede: fix use-after-free on recovery and AER handling

Set edev->cdev pointer to NULL after calling remove() callback to avoid
using of already freed object.

Fixes: ccc67ef5 ("qede: Error recovery process")
Signed-off-by: Alexander Lobakin <alobakin@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: Michal Kalderon <michal.kalderon@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -1318,6 +1318,7 @@ static void __qede_remove(struct pci_dev *pdev, enum qede_remove_mode mode)
 	if (system_state == SYSTEM_POWER_OFF)
 		return;
 	qed_ops->common->remove(cdev);
+	edev->cdev = NULL;
 
 	/* Since this can happen out-of-sync with other flows,
 	 * don't release the netdevice until after slowpath stop