fix-sgd

Author: jacquesqiao

paddle/operators/sgd_op.h

@@ -30,7 +30,7 @@ class SGDOpKernel : public framework::OpKernel {
   void Compute(const framework::ExecutionContext& ctx) const override {
     auto param = ctx.Input<Tensor>("param");
     auto grad = ctx.Input<Tensor>("grad");
-    auto param_out = ctx.Output<Tensor>(0);
+    auto param_out = ctx.Output<Tensor>("param_out");
     float lr = ctx.op_.GetAttr<float>("learning_rate");
 
     param_out->mutable_data<T>(ctx.GetPlace());