[libc-commits] [libc] [libc][NFC] fix typo in fenv type proxy headers (PR #88982)

[Nick Desaulniers via libc-commits]

https://github.com/nickdesaulniers approved this pull request.

Thanks!

Fixes: https://github.com/llvm/llvm-project/issues/88815

https://github.com/llvm/llvm-project/pull/88982