[llvm] [LoopInterchange] Prevent from undoing its own transformation (PR #127473)

[Michael Kruse via llvm-commits]

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

This directly fixes the root cause. LGTM and thanks.

Don't forget to update the summary for the commit message.

https://github.com/llvm/llvm-project/pull/127473