Fix error logging in common_distributed. (#60917)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/60917
The second line of error log didn't handle f-string properly.
Before fix:
```
exiting process with exit code: {MultiProcessTestCase.TEST_ERROR_EXIT_CODE}
```
After fix:
```
exiting process 3 with exit code: 10
```
ghstack-source-id: 132618199
Test Plan: waitforbuildbot
Reviewed By: rohan-varma
Differential Revision: D29446574
fbshipit-source-id: f806ef0470cb6aa86fe3c404e1c895514abb6488
