Add typecast to fix VS2005 build issue.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Signed-off-by: Liming Gao <liming.gao@intel.com>


git-svn-id: svn://svn.code.sf.net/p/edk2/code/trunk/edk2/UefiCpuPkg@16419 6f19259b-4bc3-4df7-8a09-765794883524