Restore missing fetch of interval functor.
Restore missing fetch of interval functor.

The w_get_functor call was accidentally deleted in 57f70b0 when a guard
clause was added to ck_intvl_punch.

AppliedLogicSystems/ALSProlog,AppliedLogicSystems/ALSProlog,AppliedLogicSystems/ALSProlog,AppliedLogicSystems/ALSProlog,AppliedLogicSystems/ALSProlog,AppliedLogicSystems/ALSProlog,AppliedLogicSystems/ALSProlog,AppliedLogicSystems/ALSProlog,AppliedLogicSystems/ALSProlog