Remove stale comment


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177410 91177308-0d34-0410-b5e6-96231b3b80d8
Update documentation of llvm-link to reflect recent cleanups.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177411 91177308-0d34-0410-b5e6-96231b3b80d8