Fix duplicated "Done" output
Summary: PhutilLibraryMapBuilder outputs "Done" twice, once implicitly from PhutilConsoleProgressBar and another explicitly.
Test Plan:
Before
> arc liberate src Finding source files... Found 350 files. Loading symbol cache... Found 0 files in cache. Analyzing 350 files with 8 subprocesses... Done. Done. Building library map... Writing map...
After
> arc liberate src Finding source files... Found 350 files. Loading symbol cache... Found 349 files in cache. Analyzing 1 files with 8 subprocesses... Done. Building library map... Writing map...
Reviewers: #blessed_reviewers, epriestley
Reviewed By: #blessed_reviewers, epriestley
Subscribers: epriestley, Korvin
Differential Revision: https://secure.phabricator.com/D9870