[XIF] The controller FSM's XIF commit tracking signals sometimes fail to be reset

Created by: michael-platzer

When the XIF interface is enabled, the controller FSM uses the signals commit_valid_q and commit_kill_q to track whether an XIF instruction already received its commit transaction. These signals must be reset every time a new XIF instruction enters the EX stage, otherwise the commit transaction never happens causing a deadlock.

The current implementation sometimes fails to reset these signals when a new instruction enters the EX stage.