Fixed controller roars persisting into loaded savegames

[Decane]

Per my comment in Decane/SRP#46:

• In xrGame\ai\monsters\controller\controller.cpp, we have:

void CController::net_Destroy()
{
	inherited::net_Destroy();

	m_aura->on_death	();
	FreeFromControl		();
}

• CControllerAura::on_death() in xrGame\ai\monsters\controller\controller_psy_aura.cpp just calls m_effector->switch_off() and then nullifies pointer m_effector. But it doesn't actually terminate the looped controller roar sounds if they are playing when CController::net_Destroy() is called.

The changes introduced here should fix the problem by forcing an immediate termination of any playing controller roar sounds when CController::net_Destroy() is called, so that they don't persist into the subsequently loaded session.

I have tried to conform as closely as possible to GSC's coding style.