ArmPlatformPkg: Use EfiEventGroupSignal from UefiLib

Use EfiEventGroupSignal from UefiLib and remove
EmptyCallbackFunction.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=298

Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

ArmPlatformPkg/Library/PlatformIntelBdsLib/IntelBdsPlatform.c

@@ -1,6 +1,6 @@
 /** @file
 
-Copyright (c) 2004 - 2008, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2004 - 2017, Intel Corporation. All rights reserved.<BR>
 Copyright (c) 2014, ARM Ltd. All rights reserved.<BR>
 
 This program and the accompanying materials
@@ -31,24 +31,6 @@ PlatformIntelBdsConstructor (
   return EFI_SUCCESS;
 }
 
-/**
-  An empty function to pass error checking of CreateEventEx ().
-
-  @param  Event                 Event whose notification function is being invoked.
-  @param  Context               Pointer to the notification function's context,
-                                which is implementation-dependent.
-
-**/
-STATIC
-VOID
-EFIAPI
-EmptyCallbackFunction (
-  IN EFI_EVENT                Event,
-  IN VOID                     *Context
-  )
-{
-}
-
 //
 // BDS Platform Functions
 //
@@ -63,24 +45,10 @@ PlatformBdsInit (
   VOID
   )
 {
-  EFI_EVENT           EndOfDxeEvent;
-  EFI_STATUS          Status;
-
   //
   // Signal EndOfDxe PI Event
   //
-  Status = gBS->CreateEventEx (
-                  EVT_NOTIFY_SIGNAL,
-                  TPL_CALLBACK,
-                  EmptyCallbackFunction,
-                  NULL,
-                  &gEfiEndOfDxeEventGroupGuid,
-                  &EndOfDxeEvent
-                  );
-  if (!EFI_ERROR (Status)) {
-    gBS->SignalEvent (EndOfDxeEvent);
-    gBS->CloseEvent (EndOfDxeEvent);
-  }
+  EfiEventGroupSignal (&gEfiEndOfDxeEventGroupGuid);
 }
 
 STATIC