Lone Survivor desperately wants to be described with clichéd buzzwords like “authentic,” “gritty” and “visceral,” but never earns such descriptors. When its four bearded Navy SEALs find themselves outnumbered by hundreds of Taliban guerrilla fighters, the action sequences’ painful physicality (there’s some bone-crunching stuntwork on display) is squandered by poor directorial choices from Peter Berg.…