AMC LOS ANGELES — “Better Call Saul” star Bob Odenkirk collapsed on the show’s New Mexico set on Tuesday and had to be hospitalized. Crew members called an ambulance that took the 58-year-old actor to a hospital, where he remained Tuesday night, said a person close to Odenkirk who was not authorized to speak publicly on the matter. It was not immediately clear what caused the collapse, or how long Odenkirk might be hospitalized. “Better Call Saul,” the spin-off prequel to “Breaking Bad,” has been shooting its sixth and final season, which is set to air on AMC next year.