utils/run_pylint.py: Prevent use of ~/.pylintrc by pylint

By default the pylint module seems to be picking up the user's
~/.pylintrc file, which could be configured to something very
different from autotest standards.

This change makes sure no local rc file is used.

  With a conflicting ~/.pylintrc present, before this change executing
  utils/run_pylint on any autotest Python source file was causing tons
  of errors, with the change the false positives are gone.

Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>