Morgan Freeman and Matt Damon are great, but Eastwood’s ‘Invictus’ is less than the sum of their parts. Some movies are impervious to criticism. Their true-life stories are so inspirational, so extraordinary, so much stranger than fiction, that quibbling over the way they’ve been presented doesn’t seem to serve much purpose. Luckily for Clint Eastwood, such stories are also largely impervious to poor storytelling. His Invictus hits all the right formula notes of both…