Fix the ordering of TCPStore's compare_set parameters (#52696)
Summary:
- Fixes the ordering of the value parameters of TCPStore's `compare_set()` in the pybind11 interop layer. The C++ API expects (old, new) while we are passing (new, old) in Python.
- Fixes the implementation of TCPStore's `compareSetHandler()` for cases where the key already exists in the store.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/52696
Test Plan: `python test/distributed/test_c10d.py`
Reviewed By: malfet, H-Huang
Differential Revision: D26616976
Pulled By: cbalioglu
fbshipit-source-id: e6a70542e837be04697b5850947924edd896dbf6
