Git check works only for last commit

[DanielChabrowski]

Hey,
git diff --check HEAD^ will not work on all commits from PR rendering using it on CI kinda useless.

I don't think there is a way to make it fully generic using git diff unless you make some assumptions like that PRs are always targeting certain branch, but if there is, I would love to know about it.

[rianquinn]

So far we haven't had any real issues, and we use this code pretty heavily on the following project:
https://github.com/Bareflank/hypervisor/blob/dev/scripts/util/bareflank_clang_tidy.sh#L74

The line is a little different as we did fix an issue with deleted files, something we should fix in this repo as well.