UefiCpuPkg/PiSmmCpuDxeSmm: Remove unnecessary function

Remove unnecessary function SetNotPresentPage(). We can directly
use ConvertMemoryPageAttributes to set a range to non-present.

Signed-off-by: Dun Tan <dun.tan@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>

UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c

@@ -1095,10 +1095,14 @@ PiCpuSmmEntry (
         mSmmShadowStackSize
         );
       if (FeaturePcdGet (PcdCpuSmmStackGuard)) {
-        SetNotPresentPage (
+        ConvertMemoryPageAttributes (
           Cr3,
+          mPagingMode,
           (EFI_PHYSICAL_ADDRESS)(UINTN)Stacks + mSmmStackSize + EFI_PAGES_TO_SIZE (1) + (mSmmStackSize + mSmmShadowStackSize) * Index,
-          EFI_PAGES_TO_SIZE (1)
+          EFI_PAGES_TO_SIZE (1),
+          EFI_MEMORY_RP,
+          TRUE,
+          NULL
           );
       }
     }