MdeModulePkg/PeiDxeDebugLibReportStatusCode: Fix comma parsing

The DebugPrintMarker function in PeiDxeDebugLibReportStatusCode/DebugLib.c
does not recognize the comma (`,`) flag in printf-style format strings.
When a driver uses format strings with thousand separators like "%,ld" to
format large numbers (e.g., 1234567 as "1,234,567"), the DebugPrintMarker
parser fails to recognize the comma flag and causes incorrect argument
extraction when building the BASE_LIST for status code reporting, leading
to unexpected or corrupted debug output in status code reports.

The change is to add the missing comma flag check to align with
BasePrintLib's format parsing logic, ensuring consistent behavior across
all print library implementations.

Signed-off-by: Ray Ni <ray.ni@intel.com>

MdeModulePkg/Library/PeiDxeDebugLibReportStatusCode/DebugLib.c

@@ -181,7 +181,7 @@ DebugPrintMarker (
     // Parse Flags and Width
     //
     for (Format++; TRUE; Format++) {
-      if ((*Format == '.') || (*Format == '-') || (*Format == '+') || (*Format == ' ')) {
+      if ((*Format == '.') || (*Format == '-') || (*Format == '+') || (*Format == ' ') || (*Format == ',')) {
         //
         // These characters in format field are omitted.
         //