A river of lava threatening Los Angeles? Why not? Following a by-the-numbers script, which shamelessly uses even a dog-in-peril plotline, “Volcano” is not great cinema. But it’s perfect entry into this summer season, what with emergency manager Tommy Lee Jones trying to bond with his daughter (Gaby Hoffman), match egos with a subordinate (Don Cheadle), knock elbows with a knowing geologist (Anne Heche) while stopping the immolation of L.A. , DataTimes ILLUSTRATION: Photo