fix load checkpoint error in test_reader (#20924)

python/paddle/fluid/contrib/slim/tests/test_reader.py

@@ -13,7 +13,6 @@
 # limitations under the license.
 
 import os
-import shutil
 import paddle
 import unittest
 import paddle.fluid as fluid
@@ -40,9 +39,6 @@ class TestReader(unittest.TestCase):
         return [('img', image.name), ('label', label.name)]
 
     def quan(self, config_file):
-        if os.path.exists('./checkpoints_quan'):
-            shutil.rmtree('./checkpoints_quan')
-
         if not fluid.core.is_compiled_with_cuda():
             return
         class_dim = 10