when make BaseTools by VS2013, LzmaEnc.c report warning C4127: conditional expression is constant, so this patch fix this issue. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Yonghong Zhu <yonghong.zhu@intel.com> Reviewed-by: Liming Gao <liming.gao@intel.com>