piglet: add missing common import

Since the common.py code wasn't being imported, piglit.py couldn't locate
the autotest_lib.client.bin module automatically.

BUG=None
TEST=`./piglit.py` now works

Change-Id: If17c06fa98dc2b07f11abd716cd44c657decbfa9
Reviewed-on: https://gerrit.chromium.org/gerrit/18389
Reviewed-by: Ilja H. Friedel <ihf@chromium.org>
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
1 file changed