message: [lldb][NFC] Give added test method a unique name
  Otherwise dotest doesn't run the test and just lets it always pass.
  Also update the comment to explain that we do directory and not
  file completion.
diff: @@ -138,8 +138,8 @@ class CommandLineCompletionTestCase(TestBase):
  ['main.cpp'])
  @skipIfFreeBSD # timing out on the FreeBSD buildbot
  - def test_log_file(self):
  - # Complete in our source directory which contains a 'main.cpp' file.
  + def test_log_dir(self):
  + # Complete our source directory.
  src_dir = os.path.dirname(os.path.realpath(__file__))
  self.complete_from_to('log enable lldb expr -f ' + src_dir,
  [src_dir + "/"])
  