‘A Private War:’ An homage to war correspondent Marie Colvin

What does it take to be a war correspondent? What kind of person is drawn to cover death and destruction, and why? Does the reporting make any difference? These questions are raised in “A Private War.” It stars Rosamund Pike as Marie Colvin, who covered atrocities in Sri Lanka, Iraq, Afghanistan, Libya, and Syria. “A Private War” is the first feature by Matthew Heineman, who’s directed award-winning documentaries, “Cartel Land” and “City of Ghosts.”