[fix] super minor, but make sure that the mem leak does not come back (#536)

benchmarks/golden_configs/oss_mnist.py

@@ -5,7 +5,7 @@ def get_golden_real_stats():
 
     return {
         "reference_speed": 660,
-        "reference_memory": 1000,
+        "reference_memory": 945,
         "reference_loss": 0.026,
     }