DeviceIndex is used as index in Slot[]. The max size of Slot[] is SD_PEIM_MAX_SLOTS. So DeviceIndex should be checked before used. Cc: Hao A Wu <hao.a.wu@intel.com> Cc: Ray Ni <ray.ni@intel.com> Signed-off-by: Shenglei Zhang <shenglei.zhang@intel.com> Reviewed-by: Hao A Wu <hao.a.wu@intel.com>