bnxt_en: Fix regression in workqueue cleanup logic in bnxt_remove_one().

A recent patch has moved the workqueue cleanup logic before
calling unregister_netdev() in bnxt_remove_one().  This caused a
regression because the workqueue can be restarted if the device is
still open.  Workqueue cleanup must be done after unregister_netdev().
The workqueue will not restart itself after the device is closed.

Call bnxt_cancel_sp_work() after unregister_netdev() and
call bnxt_dl_fw_reporters_destroy() after that.  This fixes the
regession and the original NULL ptr dereference issue.

Fixes: b16939b5 ("bnxt_en: Fix NULL ptr dereference crash in bnxt_fw_reset_task()")
Signed-off-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -12108,15 +12108,16 @@ static void bnxt_remove_one(struct pci_dev *pdev)
 	if (BNXT_PF(bp))
 		bnxt_sriov_disable(bp);
 
+	if (BNXT_PF(bp))
+		devlink_port_type_clear(&bp->dl_port);
+	pci_disable_pcie_error_reporting(pdev);
+	unregister_netdev(dev);
 	clear_bit(BNXT_STATE_IN_FW_RESET, &bp->state);
+	/* Flush any pending tasks */
 	bnxt_cancel_sp_work(bp);
 	bp->sp_event = 0;
 
 	bnxt_dl_fw_reporters_destroy(bp, true);
-	if (BNXT_PF(bp))
-		devlink_port_type_clear(&bp->dl_port);
-	pci_disable_pcie_error_reporting(pdev);
-	unregister_netdev(dev);
 	bnxt_dl_unregister(bp);
 	bnxt_shutdown_tc(bp);