THE LOUD growls out of Annapolis today will mark the annual return of the road-kill lobby -- the motorcyclists still pressing to repeal Maryland's helmet law for adults. Their pitch never changes, except to become more off the mark with each passing year of statistics and common-sense findings. The old image of romantic individualists defending their freedom to break their own heads runs counter to evidence that the helmet requirements are saving not only lives but taxpayers' money. Their repeal effort deserves swift rejection once again.