fix: remove potential double free

[adammoody]

Building with a newer gcc detected this potential variable use after a free().

We don't need this free() call at line 265 during error handling since the memory has already been freed just after the memcpy() at line 247.

https://github.com/LLNL/UnifyFS/blob/ffe0a965e0ba286b839ff622153eb9ee901f6819/server/src/unifyfs_group_rpc.c#L245-L267

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Performance enhancement (non-breaking change which improves efficiency)
• [ ] Code cleanup (non-breaking change which makes code smaller or more readable)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Testing (addition of new tests or update to current tests)
• [ ] Documentation (a change to man pages or other documentation)

Checklist:

• [ ] My code follows the UnifyFS code style requirements.
• [ ] I have updated the documentation accordingly.
• [ ] I have read the CONTRIBUTING document.
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.
• [ ] All commit messages are properly formatted.

[wangvsa]

I noticed the same error on Frontier with gcc 12.

[adammoody]

Thanks @wangvsa .