Fixed memory problem in columnwise softmax
Fixed memory problem in columnwise softmax


Former-commit-id: 0118cc6d25278464211332a77eea68094c9e2b13
clab/dynet,danielhers/dynet,danielhers/dynet,danielhers/dynet,shuheik/dynet,clab/dynet,chunyang-wen/dynet,xunzhang/dynet,chunyang-wen/dynet,clab/cnn,shuheik/dynet,danielhers/dynet,chunyang-wen/dynet,xunzhang/dynet,shuheik/dynet,danielhers/dynet,clab/dynet,shuheik/dynet,shuheik/dynet,clab/dynet,chunyang-wen/dynet,clab/dynet,danielhers/dynet,clab/cnn,xunzhang/dynet,clab/dynet,xunzhang/dynet,clab/dynet,shuheik/dynet,shuheik/dynet,clab/cnn,danielhers/dynet