Current BLOCK IO API code is using TPL_CALLBACK, but comment is saying TPL_NOTIFY. Cc: Ruiyu Ni <ruiyu.ni@intel.com> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Star Zeng <star.zeng@intel.com> Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>