[Quant][PT2E]Fix pt2e quantization maxpool input observer issue (#100961)
**Summary**
Fix the issue https://github.com/pytorch/pytorch/issues/100959. The root cause is for node of `torch.ops.aten.max_pool2d_with_indices.default`, there are 2 output node as output tensor and max indices. So in its `node.meta["val"]` is a tuple of `FakeTensors` (For example: `'val': (FakeTensor(..., size=(1, 2, s1, s1)), FakeTensor(..., size=(1, 2, s1, s1), dtype=torch.int64))`). It will fail the check of inserting observer since which only accept one `FakeTensor` case.
**Test Plan**
```
python -m pytest test_quantize_pt2e.py -k test_max_pool2d_quantizer
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/100961
Approved by: https://github.com/jerryzh168, https://github.com/jgong5
