Steve Coogan takes a glorious step backward and comes out smelling like a rose in “Alan Partridge.” It is incredibly hyperbolic to say this but Steve Coogan revisiting his preening parody of David Frost is akin to Charlie Chaplin, in middle age, revisiting the Little Tramp. Yes, quite hyperbolic indeed. But then again, Alan Partridge inspires just that sort of overreaching. You’ve never heard of Alan Partridge? Well, there are plenty of people who have, let me tell you. If you are a young British comedian today, Alan Partridge is the gold standard. Many years ago, I am sure, Mr. Coogan was more than ready to put some distance between himself and his famously goofy talk show host character. Here in the States, even Garry Shandling wishes to move far beyond “The Larry Sanders Show,” another wildly successful satire on talk shows. Coogan, however, found a way to return to the abyss and say something new, and funny.