MsWheaPkg: Add EFIAPI to relevant functions

MsWheaReportHandlerPei() is passed to ReportHwErrRecRouter() for the
MS_WHEA_ERR_REPORT_PS_FN value where that is defined as:

typedef
EFI_STATUS
(EFIAPI *MS_WHEA_ERR_REPORT_PS_FN)(
  IN MS_WHEA_ERROR_ENTRY_MD           *MsWheaEntryMD
  );

So, MsWheaReportHandlerPei() needs to include EFIAPI as well.

Similarly, MsWheaRscHandlerPei() needs EFIAPI due to the definition
of EFI_PEI_RSC_HANDLER_CALLBACK.

Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>

fixup

MsWheaPkg/MsWheaReport/Pei/MsWheaReportPei.c

@@ -31,6 +31,7 @@ Handler function that validates input arguments, and create a hob list entry for
 **/
 STATIC
 EFI_STATUS
+EFIAPI
 MsWheaReportHandlerPei (
   IN MS_WHEA_ERROR_ENTRY_MD  *MsWheaEntryMD
   )
@@ -95,6 +96,7 @@ for further processing.
 **/
 STATIC
 EFI_STATUS
+EFIAPI
 MsWheaRscHandlerPei (
   IN CONST EFI_PEI_SERVICES      **PeiServices,
   IN EFI_STATUS_CODE_TYPE        CodeType,