By Peter May They all come back. Whether it’s the money, the desire for competition, the lifestyle they thought they missed, they all come back. Kevin McHale is only the latest to leave the security of the broadcast booth to take a coaching job in the NBA. Leaving aside the question of whether the Houston Rockets know what they’re doing, the average person has to ask: what is he doing? Why would anyone want to get back to those long days, the unending