[clang-tools-extra] [NFC][clang-tidy] Unify diagnostic emission in bugprone-unsafe-functions (PR #194709)

[Endre Fülöp via cfe-commits]

gamesh411 wrote:

This NFC would have been a first step toward introducing a callback-based refinement layer for the functions that would need call-site inspection:
For example, realpath is only relevant for this check if the second argument is not nullptr, as in that case the result buffer is dynamically allocated (see https://www.man7.org/linux/man-pages/man3/realpath.3.html)
After some discussion, this checker should maybe not be made more complex prematurely, so in this regard, this change is maybe just noise on its own. I'll leave this open for a few days. If anyone deems this valuable, we can still merge it; otherwise, I'll close it.

https://github.com/llvm/llvm-project/pull/194709