Driver: Remove trailing whitespace

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211805 91177308-0d34-0410-b5e6-96231b3b80d8
Driver: Fix a misleading comment and test for what it actually did

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211806 91177308-0d34-0410-b5e6-96231b3b80d8