[clang-tools-extra] [clang-tidy] Fix false positive for cppcoreguidelines-pro-bounds-pointer-arithmetic (PR #127394)

[Baranov Victor via cfe-commits]

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

LGTM with nit.
Please rebase on fresh main and I think we can merge it, unless @carlosgalvezp has something against.

https://github.com/llvm/llvm-project/pull/127394