Replace "<>" with "!=" to be compatible with python3. Contributed-under: TianoCore Contribution Agreement 1.1 Cc: Yonghong Zhu <yonghong.zhu@intel.com> Cc: Liming Gao <liming.gao@intel.com> Signed-off-by: Gary Lin <glin@suse.com> Reviewed-by: Yonghong Zhu <yonghong.zhu@intel.com>