[c10d][flight recorder] remove unintended assignment of entry (#119748)
Summary:
auto& entry = entries_.at(*id % max_entries_);
entry = entries_.at(*id % max_entries_);
The above line of code has unintended consequence of invoking copy/assignment
of entry objects as ref itself cannot be re-assigned.
Also what could cause the crash is that the entry ref could become invalid if entries_ are
resized by other threads. and this could result in 'copy to a garbage
location'. The fix is to use a pointer which can be re-assigned after
re-acquiring the lock
Tests: python test/distributed/test_c10d_nccl.py NCCLTraceTest
Pull Request resolved: https://github.com/pytorch/pytorch/pull/119748
Approved by: https://github.com/wconstab, https://github.com/fegin
