MILWAUKEE — Gary Pettis must be so confused. Since he arrived two days ago , the Giants have looked nothing like a team that was floundering so badly it needed to bring in a new third-base coach just two months into the season. They’ve strung together two complete, generally clean efforts in a row — an accomplishment for a team that hasn’t won more than three consecutive games in any fashion all year. And it has come against no slouch. Casey Schmitt slugged his 13th home run of the season on