* Spain's credit downgrade, weak European data hits oil * Absence of QE3 hint from Bernanke still a factor * Coming up: API weekly petroleum data, Tuesday NEW YORK, June 8 (Reuters) - U.S. crude futures fell for a second day in a row on Friday as Spain's banking troubles, broader European economic problems and fading hopes about more U.S. Federal Reserve monetary stimulus darkened the outlook for global oil demand. For the week, however, U.S. crude rose more than 1 percent,