Merge pull request #15179 from sneaxiy/fix_crf_grad_lod

Fix crf grad lod share

paddle/fluid/operators/linear_chain_crf_op.cc

@@ -230,10 +230,12 @@ class LinearChainCRFGradOp : public framework::OperatorWithKernel {
 
     if (ctx->HasOutput(framework::GradVarName("Emission"))) {
       ctx->SetOutputDim(framework::GradVarName("Emission"), emission_exps_dims);
+      ctx->ShareLoD("Emission", framework::GradVarName("Emission"));
     }
     if (ctx->HasOutput(framework::GradVarName("Transition"))) {
       ctx->SetOutputDim(framework::GradVarName("Transition"),
                         transition_exps_dims);
+      ctx->ShareLoD("Transition", framework::GradVarName("Transition"));
     }
   }