Specify --dir flag explicitly in the other logserver init scripts.

This is a follow up to
https://skia.googlesource.com/buildbot/+/c1ec33e64fb7696a1a908abd2280dce38b3a4222

BUG=skia:3147
R=rmistry@google.com

Review URL: https://codereview.chromium.org/750773004