By Matt Hladik The Milwaukee Bucks have won twice in Boston during their Eastern Conference semifinal series. They’ll need another win today in Game 7 to advance to the next round. The Celtics have mitigated their home court struggles by winning twice in Milwaukee, but will have to handle their business at TD Garden this afternoon. Ahead of this crucial do-or-die contest, ESPN’s Stephen A. Smith issued a “warning” to Boston on NBA Countdown. “I will say this: The Bucks won Game 1 in Boston. They won Game 5 in Boston,” Smith said, via NESN.com. “The Boston Celtics had damn well better not lose …