Add EFIAPI in CatPrint library function. Every function which uses variable list need explicit use EFIAPI to force use MS ABI. This change is needed to pass CLANG38 build. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Steven Shi <steven.shi@intel.com> Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>