Fix the bug in cipd recipe module preventing to add the package root as a dir.

R=vadimsh@chromium.org

Bug:

Change-Id: Ia9b7adbf7f9b0e0e6dd4158934197e4f69ba993e
Reviewed-on: https://chromium-review.googlesource.com/483850Reviewed-by: Vadim Shtayura <vadimsh@chromium.org>
Commit-Queue: Nodir Turakulov <nodir@chromium.org>