UefiCpuPkg/MicrocodeMeasurementDxe: Fix exception

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4360

An incorrect format specifier is being used in a DEBUG print,
specifically, a variable of type EFI_STATUS was being printed with
the %a format specifier (pointer to an ASCII string), thus the value of
the Status variable was being treated as the address of a string,
leading to a CPU exception, when encountered this bug manifests itself
as a hang near "Ready to Boot Event", with the last DEBUG print being
"INFO: Got MicrocodePatchHob with microcode patches starting address"
followed by a CPU Exception dump.

Signed-off-by: Darbin Reyes <darbin.reyes@intel.com>
Reviewed-by: Jacob Narey <jacob.narey@intel.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>

UefiCpuPkg/MicrocodeMeasurementDxe/MicrocodeMeasurementDxe.c

@@ -238,7 +238,7 @@ MeasureMicrocodePatches (
        TotalMicrocodeSize)
       );
   } else {
-    DEBUG ((DEBUG_ERROR, "ERROR: TpmMeasureAndLogData failed with status %a!\n", Status));
+    DEBUG ((DEBUG_ERROR, "ERROR: TpmMeasureAndLogData failed with status %r!\n", Status));
   }
 
   FreePool (Offsets);