During eviction of FreeSpace nodes that reside on eviction pages we iterate
throug the list node-by-node, unlinking only those that reside on eviction
pages. We failed to properly update end_ if nodes were evicted are encountering
nodes that that are left as is.

BUG=chromium:539356
LOG=N
R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/1411263002

Cr-Commit-Position: refs/heads/master@{#31383}