[llvm] [LV] Fix runtime-VF logic when generating RT-checks (PR #130118)

[Ramkumar Ramachandra via llvm-commits]

artagnon wrote:

@fhahn Very sorry! The patch seemed correct to me, but digging deeper, I found it to be deeply incorrect. You're right, and it is the cost that changed.

https://github.com/llvm/llvm-project/pull/130118