message: format: fix the ability to find buildifier in non-standard path.
diff: @@ -14,8 +14,6 @@ import shutil
  import subprocess
  import sys
  -os.putenv("BUILDIFIER_BIN", "/usr/local/bin/buildifier")
  -
  tools = os.path.dirname(os.path.realpath(__file__))
  tmp = os.path.join(os.getenv('TEST_TMPDIR', "/tmp"), "check_format_test")
  src = os.path.join(tools, 'testdata', 'check_format')
  