Cleanup of the fix done recently for a lldb-mi hang on OSX.
It was observed that we dont need to set stdin to unbuffered and setting console
to non-canonical mode.

Patch originally came from "Ilia K <ki.stfu@gmail.com>"



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@223353 91177308-0d34-0410-b5e6-96231b3b80d8