This commit refines the logic for main(). It makes the logic more straightforward to prevent possible mis-reports by static code checkers. Cc: Yonghong Zhu <yonghong.zhu@intel.com> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Hao Wu <hao.a.wu@intel.com> Reviewed-by: Liming Gao <liming.gao@intel.com>