[llvm] [llvm-bolt] Modify `getLibPath` to enable `--runtime-instrumentation-lib` option handle full path correctly.(llvm#99772) (PR #99806)

[Zimo Ji via llvm-commits]

lltsdyp wrote:

Hmm, I forgot to verify the existence of the runtime instrumentation library so I modified it and open a new PR

https://github.com/llvm/llvm-project/pull/99806