The late night wars are over and peace has returned to the 11:30 p.m. time slot. With a nod to Dorothy, Jay Leno returned to the Tonight Show last night repeating, “There’s no place like home.” The last nine months, from his ill-fated move to prime time to his public spat with temporary Tonight Show host Conan O’Brien, were all a dream. And Leno’s Tonight Show, which he hosted for 17 years before his 2009 hiatus, seems to be sticking to his old formula with what’s-in-the-news one-liners and A-list celebrity guests. (Monday night, those included Toyota and Tiger Woods jokes before appearances by Jamie Foxx and Lindsey Vonn.) The only thing that was really new, Leno said, was his desk.