Fix typo in print-json-test-results when checking for flaky results.

R=ojan@chromium.org
BUG=

Review URL: https://codereview.chromium.org/54373008

git-svn-id: svn://svn.chromium.org/blink/trunk@161105 bbb929c8-8fbe-4397-9dbb-9b2b20218538