It's the final tune up for the starters and the final exam for 22 players as the Packers meet the Chiefs in Kansas City Thursday night.   The first stringers will play only a series, some starters might get a few extra snaps like rookie safety Morgan Burnett, but this game is all about the backups battling for a job.   The final roster of 53 must be set by Saturday.   The Packers will likely give extended looks to some veterans who have found their way onto the bubble, players like Alan Barbre, Brenno Giacommini, Jarret Bush and Charlie Peprah.   Long shots like Frank Zombo, Sam Shields and Jason Chery can solidify their roster spots with solid games.   Here's a quick trip through the locker room to hear what some coaches and players have to say about the pre-season finale.