People enjoy looking at Channing Tatum. That’s good, because his picture’s in the dictionary next to “derivative.” Want to see Tatum, big ass explosions and helicopters on a big screen? By all means, go and see “White House Down” (2013). Otherwise, save your money and wait for Netflix. It’s not a bad action movie (yes, I’m damning it with faint praise). But it has no original ideas. It steals its plot (and Bruce Willis’ dirty old shirt) from “Die Hard,” sprinkles in a little “True Lies” and gives you a knockoff 98 days after the release of “Olympus Has Fallen.”