Remove variable that is currently unused.

BUG=http://code.google.com/p/v8/issues/detail?id=502
Review URL: http://codereview.chromium.org/392001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3267 ce2b1a6d-e550-0410-aec6-3dcde31c8c00