fix mac test_data_baalancance

python/paddle/fluid/tests/unittests/test_data_balance.py

@@ -84,7 +84,7 @@ class TestDataBalance(unittest.TestCase):
         self.data_file_name = './data_balance_test.recordio'
         self.lod_data_file_name = './data_balance_with_lod_test.recordio'
         self.total_ins_num = 50
-        self.batch_size = 10
+        self.batch_size = 12
         self.prepare_data()
         self.prepare_lod_data()