UefiCpuPkg: Change complex DEBUG_CODE() to DEBUG_CODE_BEGIN/END()

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3767

Update use of DEBUG_CODE(Expression) if Expression is a complex code
block with if/while/for/case statements that use {}.

Cc: Andrew Fish <afish@apple.com>
Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Michael Kubacki <michael.kubacki@microsoft.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>

UefiCpuPkg/Library/MpInitLib/MpLib.c

@@ -2155,7 +2155,7 @@ MpInitLibInitialize (
   //
   // Dump the microcode revision for each core.
   //
-  DEBUG_CODE (
+  DEBUG_CODE_BEGIN ();
     UINT32 ThreadId;
     UINT32 ExpectedMicrocodeRevision;
     CpuInfoInHob = (CPU_INFO_IN_HOB *) (UINTN) CpuMpData->CpuInfoInHob;
@@ -2176,7 +2176,7 @@ MpInitLibInitialize (
           ));
       }
     }
-  );
+  DEBUG_CODE_END ();
   //
   // Initialize global data for MP support
   //