TestHFileCleaner can fail after addition of ManualMobMaintHFileCleaner

After https://github.com/apache/hbase/commit/a881678ef4e0ffcd94add935729424c6e2567356 testHFileCleaning can fail due to some lazy directory creation in the test. ManualMobMaintHFileCleaner needs to get the table directory (and indirectly namespace) which can fail since the test itself only creates the file within the archive directory. It does not contain the archive/data/namespace/table/region/cf/ which the ManualMobMaintHFileCleaner expects.

This is a relatively minor issue, but we saw this test fail when running on EC2 because we had an 'invalid namespace' (because it had a '-' in the path).

FYI busbey