Small fix for micro benchmark code (#711)

Summary:
There seems to be some problems running benchmark_aq.py:
```
torch._dynamo.exc.Unsupported: torch.* op returned non-Tensor int call_function <method 'size' of 'torch._C.TensorBase' objects>
```
when we run the benchmark with multiple shapes sometimes. But the problem will be gone if we reset the dynamo caches before
each benchmark run

Test Plan:
python benchmarks/benchmark_aq.py

Reviewers:

Subscribers:

Tasks:

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Author: jerryzh168

benchmarks/benchmark_aq.py

@@ -17,6 +17,7 @@
     _replace_with_custom_fn_if_matches_filter,
 )
 import copy
+from torchao.utils import unwrap_tensor_subclass
 
 def _int8wo_api(mod, **kwargs):
     if TORCH_VERSION_AT_LEAST_2_4:
@@ -133,15 +134,17 @@ def _bench_quantized_tensor_subclass_perf(api, ref_api, M, N, K, kwargs=None):
     WARMUP = 20
     RUNS = 100
 
+    torch._dynamo.reset()
     m_ref = torch.compile(m_ref, mode='max-autotune', fullgraph=True)
     benchmark_model(m_ref, WARMUP, example_inputs)
     ref_elapsed_time = benchmark_model(m_ref, RUNS, example_inputs)
 
+    torch._dynamo.reset()
     m = torch.compile(m, mode='max-autotune', fullgraph=True)
     benchmark_model(m, WARMUP, example_inputs)
     elapsed_time = benchmark_model(m, RUNS, example_inputs)
 
-
+    torch._dynamo.reset()
     m_bf16 = torch.compile(m_bf16, mode='max-autotune', fullgraph=True)
     benchmark_model(m_bf16, WARMUP, example_inputs)
     bf16_elapsed_time = benchmark_model(m_bf16, RUNS, example_inputs)