[clang-tools-extra] [clang-tidy] Clarify diagnostics of bugprone-sizeof-expression (PR #95550)

[Donát Nagy via cfe-commits]

NagyDonat wrote:

If there is no feedback on the separator mark bikeshedding (which is understandable -- it's a very minor question), I'll merge this commit on Thursday.

https://github.com/llvm/llvm-project/pull/95550