UefiCpuPkg/PiSmmCpuDxeSmm: Add check to avoid NULL ptr dereference

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
1 file changed