[patch 1/2] MdeModulePkg/BMMUiLib: Set Handle to NULL after uninstall protocol

["Dandan Bi" <dandan.bi@intel.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1728

Currently Emulator meets ASSERT when enter setup->Continue->enter setup.
When re-enter setup, the BmmDriverHandle in BMMUiLib Constructor
is not NULL which cause InstallMultipleProtocolInterfaces failure,
then ASSERT. So here set BmmDriverHandle to NULL after uninstalling
protocols on it in Destructor function to avoid this issue.

Cc: Liming Gao <liming.gao@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Hao Wu <hao.a.wu@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Signed-off-by: Dandan Bi <dandan.bi@intel.com>
---
 .../Library/BootMaintenanceManagerUiLib/BootMaintenance.c      | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/MdeModulePkg/Library/BootMaintenanceManagerUiLib/BootMaintenance.c b/MdeModulePkg/Library/BootMaintenanceManagerUiLib/BootMaintenance.c
index 2167d3a5e8..28592f9f47 100644
--- a/MdeModulePkg/Library/BootMaintenanceManagerUiLib/BootMaintenance.c
+++ b/MdeModulePkg/Library/BootMaintenanceManagerUiLib/BootMaintenance.c
@@ -1,9 +1,9 @@
 /** @file
 The functions for Boot Maintainence Main menu.
 
-Copyright (c) 2004 - 2018, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2004 - 2019, Intel Corporation. All rights reserved.<BR>
 SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
 
 #include "BootMaintenanceManager.h"
@@ -1761,9 +1761,10 @@ BootMaintenanceManagerUiLibDestructor (
          &mBmmCallbackInfo->BmmConfigAccess,
          NULL
          );
 
   FreePool (mBmmCallbackInfo->LoadContext);
+  mBmmCallbackInfo->BmmDriverHandle = NULL;
 
   return EFI_SUCCESS;
 }
 
-- 
2.18.0.windows.1