UefiCpuPkg/Cpuid: Remove wrong while-loop check after for-loop

UefiCpuPkg/Cpuid: Remove wrong while-loop check after for-loop

while-loop check should not co-exist with for-loop. This should be typo when we
check-in the original code. We should keep one loop only.

This issue caused CLANG38 build failure reported by
https://tianocore.acgmultimedia.com/show_bug.cgi?id=148

Contributed-under: TianoCore Contribution Agreement 1.0
Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>