Fix the doc of hmc to use the same code as the code file!
Fix the doc of hmc to use the same code as the code file!

This was reported by Chris Fonnesbeck in Theano issue gh-1581.

SYSUNLP/DeepLearningTutorials,liangz0707/DeepLearningTutorials,shijiaxing/DeepLearningTutorials,yukoba/DeepLearningTutorials,AveRapina/DeepLearningTutorials,pombredanne/DeepLearningTutorials,linan7788626/DeepLearningTutorials,heaven00/DeepLearningTutorials,cainiaocome/DeepLearningTutorials,ericzhouh/DeepLearningTutorials,abergeron/DeepLearningTutorials,AveRapina/DeepLearningTutorials,cainiaocome/DeepLearningTutorials,iamtrask/DeepLearningTutorials,mmolero/DeepLearningTutorials,OlafLee/DeepLearningTutorials,webeng/DeepLearningTutorials,heaven00/DeepLearningTutorials,jyb002/DeepLearningTutorials,haojunyu/DeepLearningTutorials,marchick209/DeepLearningTutorials,SYSUNLP/DeepLearningTutorials,webeng/DeepLearningTutorials,jyb002/DeepLearningTutorials,agarbuno/DeepLearningTutorials,jorik041/DeepLearningTutorials,FighterLYL/DeepLearningTutorials,NanYoMy/DeepLearningTutorials,yukoba/DeepLearningTutorials,marchick209/DeepLearningTutorials,mmolero/DeepLearningTutorials,agarbuno/DeepLearningTutorials,ericzhouh/DeepLearningTutorials,xuezhisd/DeepLearningTutorials,linan7788626/DeepLearningTutorials,abergeron/DeepLearningTutorials,FighterLYL/DeepLearningTutorials,liangz0707/DeepLearningTutorials,iamtrask/DeepLearningTutorials,shijiaxing/DeepLearningTutorials,NanYoMy/DeepLearningTutorials,EugenePig/DeepLearningTutorials,webeng/DeepLearningTutorials,sha8e/DeepLearningTutorials,pengsun/DeepLearningTutorials,sha8e/DeepLearningTutorials,EugenePig/DeepLearningTutorials,pengsun/DeepLearningTutorials,jorik041/DeepLearningTutorials,pombredanne/DeepLearningTutorials,haojunyu/DeepLearningTutorials,OlafLee/DeepLearningTutorials,xuezhisd/DeepLearningTutorials