i40e: Remove timer and task only if created

In some error scenarios, we may find ourselves trying to remove a
non-existent timer or worktask.  This causes the kernel some bit
of consternation, so don't do it.

Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -11306,8 +11306,10 @@ static void i40e_remove(struct pci_dev *pdev)
 	/* no more scheduling of any task */
 	set_bit(__I40E_SUSPENDED, &pf->state);
 	set_bit(__I40E_DOWN, &pf->state);
-	del_timer_sync(&pf->service_timer);
-	cancel_work_sync(&pf->service_task);
+	if (pf->service_timer.data)
+		del_timer_sync(&pf->service_timer);
+	if (pf->service_task.func)
+		cancel_work_sync(&pf->service_task);
 
 	if (pf->flags & I40E_FLAG_SRIOV_ENABLED) {
 		i40e_free_vfs(pf);