Fix missing error import.

Caught this when pushing new autotest changes. Seems like the offending
change was introduced last week.

BUG=None
TEST=Running as a local change on prod.

Change-Id: I86a00d1ce0fa005f2f51837a6710d817ac134c7d
Reviewed-on: https://gerrit.chromium.org/gerrit/43483
Commit-Queue: Chris Sosa <sosa@chromium.org>
Reviewed-by: Chris Sosa <sosa@chromium.org>
Tested-by: Chris Sosa <sosa@chromium.org>
1 file changed