staging: sbe-2t3e3: Fix possible reuse of freed memory in timer function

Do not call kfree() till timer function is finished.

[This was found using grep. Compilation tested only]
Signed-off-by: NKirill Tkhai <tkhai@yandex.ru>
CC: Joe Perches <joe@perches.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/sbe-2t3e3/module.c

@@ -122,7 +122,7 @@ static void t3e3_remove_card(struct pci_dev *pdev)
 	struct channel *channel0 = pci_get_drvdata(pdev);
 	struct card *card = channel0->card;
 
-	del_timer(&card->timer);
+	del_timer_sync(&card->timer);
 	if (has_two_ports(channel0->pdev)) {
 		t3e3_remove_channel(&card->channels[1]);
 		pci_dev_put(card->channels[1].pdev);