Hollywood’s lackluster summer, filled with less-than-stellar releases, nevertheless ended with a hip-hip-hoorah: The cheerleading comedy “Bring It On” finished in the No. 1 slot in the Labor Day weekend race. (Top 10 list follows.) As for the summer’s overall performance, movies will have grossed an estimated $2.75 billion, making this the season’s second-best ever, after last year’s $2.9 billion, according to Exhibitor Relations Co. The downside is that ticket prices are up, which means that movie attendance is down, possibly 10-15%. This summer’s big winners were “Mission: Impossible 2” ($200 million), “The Perfect Storm” ($175 million), “X-Men” and “Scary Movie” (both $150 million), and “What Lies Beneath” ($130 million). Also topping $100 million: “Nutty Professor II: The Klumps,” “Big Momma’s House,” “Chicken Run” and “The Patriot.” The Labor Day weekend results: