(By Janet Maslin, New York Times) ‘HOW IT ENDED: New and Collected Stories'By Jay McInerney; 331 pages. Alfred A. Knopf. $25.95Jay McInerney's writing career has lasted nearly three decades, and what has he got to show for it? Seven novels, but the world at large can name only his first: “Bright Lights, Big City.”Now comes the game-changer: “How It Ended,” a collection that comprises 26 short stories spanning 26 years.