Relax KnownDll warning to log
Relax KnownDll warning to log

Downgrades a KnownDll warning to just a log statement as it is not relevant
to today's tool builds.

Review-URL: https://codereview.appspot.com/276940043

AmesianX/dynamorio,AmesianX/dynamorio,AmesianX/dynamorio,AmesianX/dynamorio,AmesianX/dynamorio