[Release] Remove usage of roll ref

[Release] Remove usage of roll ref

The roll ref is no longer used because we
simply roll the lkgr ref.

LOG=N
NOTRY=true
R=machenbach@chromium.org

Committed: https://crrev.com/e267936c4237050bd0f468d9420192479dcd2ec8
Cr-Commit-Position: refs/heads/master@{#31140}

[Michael Hablich, 2015-10-07 10:13:41]

PTAL

[Michael Achenbach, 2015-10-07 10:24:15]

lgtm

[Michael Hablich, 2015-10-07 10:24:55]

The CQ bit was checked by hablich@chromium.org

[commit-bot: I haz the power, 2015-10-07 10:25:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1391153002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1391153002/1

[commit-bot: I haz the power, 2015-10-07 10:27:26]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-07 10:27:34]

Patchset 1 (id:??) landed as
https://crrev.com/e267936c4237050bd0f468d9420192479dcd2ec8
Cr-Commit-Position: refs/heads/master@{#31140}