Bluetooth: hci_sync: Fix not setting adv set duration

10bbffa3 attempted to fix the use of rotation duration as
advertising duration but it didn't change the if condition which still
uses the duration instead of the timeout.

Fixes: 10bbffa3 ("Bluetooth: Fix using advertising instance duration as timeout")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>