The Yankees signed up to sponsor the Roger Clemens reunion tour for just these types of games. Instead of asking an anxious rookie to stop a losing streak, they could turn to one of the greatest pitchers in history. Clemens would slap a few backs, utter some of his homespun Texas wisdom and all would be right again. That he would cost roughly $872,000 per start was an afterthought. But baseball's John Wayne is running out of bullets, and the cavalry isn't much help these days. Clemens held the Baltimore Orioles down for five innings last night but not the sixth, as the Yankees were beaten 4-0 before a sweaty 35,776 at Camden Yards,