pytorch

0eee81aa - [quant] Modify APoT qparam quantization levels calculation (#80303)

[quant] Modify APoT qparam quantization levels calculation (#80303) ### Summary: This PR updates an error in the the computation for APoT quantization levels to match the formula defined in the APoT paper: https://arxiv.org/pdf/1909.13144.pdf. ### Test Plan: Run unit tests with:` python pytorch/test/quantization/core/experimental/test_nonuniform_observer.py` Pull Request resolved: https://github.com/pytorch/pytorch/pull/80303 Approved by: https://github.com/dzdang