test=develop, fix using create_parameter with attr set to False error (#16115)

python/paddle/fluid/layer_helper_base.py

@@ -270,6 +270,9 @@ class LayerHelperBase(object):
         attr = copy.deepcopy(attr)
         if attr is None:
             attr = ParamAttr._to_attr(attr)
+        if not attr:
+            return None
+
         assert isinstance(attr, ParamAttr)
         suffix = 'b' if is_bias else 'w'
         if attr.name is None: