Short review of three little words: Way. Too. Long. Nearly two-and-a-half hours — what? — to remake a 1984 movie about a kid who learns karate from a master so he can beat up bullies. (Peter Travers reviews The Karate Kid in his weekly video series, “At the Movies With Peter Travers.”) The original had New Jersey teen Ralph Macchio learning karate from the great Pat Morita in California. The reboot has Detroit kid Jaden Smith, the 12-year-old son of Will and Jada, learning kung fu from the great Jackie Chan in China (cue the travelogue footage). For a movie whose outcome is never in doubt, the padding is punishing.