The latest chapter of the series finds “Riggs” (Mel Gibson) and “Murtaugh” (Danny Glover), whose bodies seem to ache as much as the dialogue does, launching into action with a bang. This time around, Chinese Triad gangs are involved in smuggling people and counterfeiting money—activities that could spark a full-blown war between the sharply dressed “Wah Sing Ku” (Jet Li) and local crime boss “Uncle Benny” (Kim Chan).…