S&P 500 drug distributor Cardinal Health (CAH) easily topped fiscal fourth-quarter earnings forecasts despite a revenue shortfall. Shares of the S&P 500 drug distributor held in a buy zone. Rival McKesson (MCK), which whipsawed after its earnings report last week, has climbed back near a buy point. Cencora (COR), another big S&P 500 drug distributor, also is near a buy…