net: ena: fix missing lock during device destruction

BugLink: http://bugs.launchpad.net/bugs/1792044

acquire the rtnl_lock during device destruction to avoid
using partially destroyed device.

ena_remove() shares almost the same logic as ena_destroy_device(),
so use ena_destroy_device() and avoid duplications.
Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 944b28aa linux-next)
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Acked-by: Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/net/ethernet/amazon/ena/ena_netdev.c

@@ -3433,24 +3433,18 @@ static void ena_remove(struct pci_dev *pdev)
 
 	unregister_netdev(netdev);
 
-	/* Reset the device only if the device is running. */
+	/* If the device is running then we want to make sure the device will be
+	 * reset to make sure no more events will be issued by the device.
+	 */
 	if (test_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags))
-		ena_com_dev_reset(ena_dev, adapter->reset_reason);
-
-	ena_free_mgmnt_irq(adapter);
+		set_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags);
 
-	ena_disable_msix(adapter);
+	rtnl_lock();
+	ena_destroy_device(adapter, true);
+	rtnl_unlock();
 
 	free_netdev(netdev);
 
-	ena_com_mmio_reg_read_request_destroy(ena_dev);
-
-	ena_com_abort_admin_commands(ena_dev);
-
-	ena_com_wait_for_abort_completion(ena_dev);
-
-	ena_com_admin_destroy(ena_dev);
-
 	ena_com_rss_destroy(ena_dev);
 
 	ena_com_delete_debug_area(ena_dev);