“Green Book” is the worst best picture Oscar winner since “Crash,” and I don’t make the comparison lightly. Like that 2005 movie, Peter Farrelly’s interracial buddy dramedy is insultingly glib and hucksterish, a self-satisfied crock masquerading as an olive branch. It reduces the long, barbaric and ongoing history of American racism to a problem, a formula, a dramatic equation that can be balanced and solved. “Green Book” is an embarrassment; the film industry’s unquestioning embrace of it is another.