Fix json parse error for profiler call stack (#57099)
Summary:
The call stack in profiler result json file lacks surrounding double quotes, and result in json parse error.
This PR just add it.
ilia-cher
Pull Request resolved: https://github.com/pytorch/pytorch/pull/57099
Reviewed By: gdankel
Differential Revision: D28324182
Pulled By: ilia-cher
fbshipit-source-id: dc479a023bb25de27c414629a27d624d64457c3e
