[FIX] fix pickle model bugs

learnware/tests/templates/pickle_model.py

@@ -16,8 +16,8 @@ class PickleLoadedModel(BaseModel):
     ):
         super(PickleLoadedModel, self).__init__(input_shape=input_shape, output_shape=output_shape)
         dir_path = os.path.dirname(os.path.abspath(__file__))
-        self.pickle_filepath = os.path.join(pickle_filepath, dir_path)
-        with open(pickle_filepath, "rb") as fd:
+        self.pickle_filepath = os.path.join(pickle_filename, dir_path)
+        with open(pickle_filename, "rb") as fd:
             self.model = pickle.load(fd)
         self.predict_method = predict_method
         self.fit_method = fit_method