hgext/__init__.py

bdiff-torture: fix pyflakes warning reporting undefined name 'inst'

Looks like I got a latest version of pyflakes somehow or it's running on py3 and
it spotted this.

Differential Revision: https://phab.mercurial-scm.org/D6757

from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)