Fix compilation after r22461: removed now unused var

BUG=none
LOG=n
TBR=danno@chromium.org

Review URL: https://codereview.chromium.org/400123002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22462 ce2b1a6d-e550-0410-aec6-3dcde31c8c00