fixing argument type
fixing argument type


Former-commit-id: 89f5dea4218fb4eb2a7203af1fd84921448f558a
xunzhang/dynet,xunzhang/dynet,danielhers/dynet,danielhers/dynet,danielhers/dynet,shuheik/dynet,chunyang-wen/dynet,clab/dynet,chunyang-wen/dynet,chunyang-wen/dynet,shuheik/dynet,danielhers/dynet,clab/cnn,shuheik/dynet,clab/dynet,clab/cnn,clab/dynet,xunzhang/dynet,clab/dynet,clab/dynet,clab/dynet,shuheik/dynet,shuheik/dynet,danielhers/dynet,clab/dynet,danielhers/dynet,shuheik/dynet,xunzhang/dynet,danielhers/dynet,chunyang-wen/dynet,shuheik/dynet,clab/cnn