patchelf change binary's librt.so.1 directory to default system directory.

[cmd120]

I ran pathelf on my clang to use newer shared libraries but generated binary didn't link librt.so.1 in my specified directory but system's librt.so.1. Even if I rebuilt clang to use my librt.so.1, after ran patchelf it was changed to system's librt.so.1.