Minor fixups to documentation for Process::Launch()/DoLaunch().

The code had moved forward with changes for using ProcessLaunchInfo,
but the documentation still referred to arguments that no longer
get passed to these methods.


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@213965 91177308-0d34-0410-b5e6-96231b3b80d8