[CHERRY-PICK] UefiCpuPkg/PiSmmCpuDxeSmm: Simplify RunningApCount decr…

…ement

To decrease the count of RunningApCount, InterlockedDecrement is
enough to achieve that.

This patch is to simplify RunningApCount decrement.

Cc: Laszlo Ersek <[email protected]>
Cc: Eric Dong <[email protected]>
Cc: Ray Ni <[email protected]>
Cc: Zeng Star <[email protected]>
Cc: Gerd Hoffmann <[email protected]>
Cc: Rahul Kumar <[email protected]>
Signed-off-by: Jiaxin Wu <[email protected]>
Reviewed-by: Ray Ni <[email protected]>
(cherry picked from commit ff9bd3f)

UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c

@@ -1325,7 +1325,7 @@ InternalSmmStartupAllAPs (
       // Decrease the count to mark this processor(AP or BSP) as finished.
       //
       if (ProcToken != NULL) {
-        WaitForSemaphore (&ProcToken->RunningApCount);
+        InterlockedDecrement (&ProcToken->RunningApCount);
       }
     }
   }