Update xp release dual core moz expectations.

Recent red in vm_peak_b looks flaky to me.

BUG=none
TEST=xpdual moz is green
TBR=nsylvain@chromium.org

Review URL: http://codereview.chromium.org/3138003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@55595 0039d316-1c4b-4281-b951-d872f2087c98