fix bug in max
fix bug in max

kaishengyao/cnn,kamigaito/cnn,cherryc/dynet,yoavg/cnn,Peilun-Li/dynet,Peilun-Li/dynet,mitchellstern/dynet,cherryc/dynet,Peilun-Li/dynet,Abasyoni/dynet,mrzu/cnn,dhgarrette/cnn,mitchellstern/dynet,cherryc/dynet,dhgarrette/cnn,kaishengyao/cnn,yanweifu/cnn,Abasyoni/dynet,Abasyoni/dynet,dhgarrette/cnn,yoavg/cnn,kamigaito/cnn