fix update loss scaling (#43487)

paddle/fluid/operators/amp/update_loss_scaling_op.cc

@@ -107,7 +107,7 @@ class UpdateLossScalingOpMaker : public framework::OpProtoAndCheckerMaker {
     AddOutput("LossScaling", "(Tensor) 1-dim tensor, updated loss scaling.");
     AddOutput("OutGoodSteps", "(Tensor) 1-dim tensor, pdated good steps.");
     AddOutput("OutBadSteps", "(Tensor) 1-dim tensor, updated bad steps.");
-    AddOutput("StopUpdate",
+    AddInput("StopUpdate",
              "(Tensor) 1-dim tensor. Stop updating loss scaling, and just "
              "zero inputs. It has higher priority than Attr(stop_update).")
         .AsDispensable();