remove grad X

test=develop

paddle/fluid/operators/cvm_op.cc

@@ -131,11 +131,9 @@ class CVMGradOpDescMaker : public framework::SingleGradOpDescMaker {
   std::unique_ptr<framework::OpDesc> Apply() const override {
     std::unique_ptr<framework::OpDesc> op(new framework::OpDesc());
     op->SetType("cvm_grad");
-    op->SetInput("X", Input("X"));
     op->SetInput("CVM", Input("CVM"));
     op->SetInput(framework::GradVarName("Y"), OutputGrad("Y"));
     op->SetOutput(framework::GradVarName("X"), InputGrad("X"));
-    op->SetOutput(framework::GradVarName("CVM"), InputGrad("CVM"));
     op->SetAttrMap(Attrs());
     return op;
   }