Change the size in test_LayerGrad and pass unit test

paddle/gserver/tests/test_LayerGrad.cpp

@@ -1679,8 +1679,8 @@ TEST(Layer, smooth_l1) {
   TestConfig config;
   config.layerConfig.set_type("smooth_l1");
 
-  config.inputDefs.push_back({INPUT_DATA, "layer_0", 1, 0});
-  config.inputDefs.push_back({INPUT_DATA_TARGET, "layer_1", 1, 0});
+  config.inputDefs.push_back({INPUT_DATA, "layer_0", 200, 0});
+  config.inputDefs.push_back({INPUT_DATA_TARGET, "layer_1", 200, 0});
   config.layerConfig.add_inputs();
   config.layerConfig.add_inputs();