Fix the path to factory log

The path to factory test log has changed. Let's change it in factorylog
init script.

BUG=none
TEST=Check we can see log in VT3.

Change-Id: Id21ec47bad4a6d8c27ddbed7a090b47b8e01a84f
Reviewed-on: https://gerrit.chromium.org/gerrit/27263
Reviewed-by: Jon Salz <jsalz@chromium.org>
Reviewed-by: Hsinyu Chao <hychao@chromium.org>
Commit-Ready: Vic Yang <victoryang@chromium.org>
Tested-by: Vic Yang <victoryang@chromium.org>