[patch] IntelFrameworkModulePkg/LegacyBootMaintUiLib: Add NULL pointer check

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

mLegacyBootOptionPrivate pointer is initialized in Constructor function
with if condition check, but it's used in Destructor function directly
without any check. Now add the NULL pointer check.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Dandan Bi <dandan.bi@intel.com>
---
 .../Library/LegacyBootMaintUiLib/LegacyBootMaintUi.c                  | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/IntelFrameworkModulePkg/Library/LegacyBootMaintUiLib/LegacyBootMaintUi.c b/IntelFrameworkModulePkg/Library/LegacyBootMaintUiLib/LegacyBootMaintUi.c
index 740c95c..a4828b7 100644
--- a/IntelFrameworkModulePkg/Library/LegacyBootMaintUiLib/LegacyBootMaintUi.c
+++ b/IntelFrameworkModulePkg/Library/LegacyBootMaintUiLib/LegacyBootMaintUi.c
@@ -13,11 +13,11 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 **/
 
 
 #include "LegacyBootMaintUi.h"
 
-LEGACY_BOOT_OPTION_CALLBACK_DATA  *mLegacyBootOptionPrivate;
+LEGACY_BOOT_OPTION_CALLBACK_DATA  *mLegacyBootOptionPrivate = NULL;
 EFI_GUID  mLegacyBootOptionGuid     = LEGACY_BOOT_OPTION_FORMSET_GUID;
 CHAR16    mLegacyBootStorageName[]  = L"LegacyBootData";
 BBS_TYPE  mBbsType[] = {BBS_FLOPPY, BBS_HARDDISK, BBS_CDROM, BBS_EMBED_NETWORK, BBS_BEV_DEVICE, BBS_UNKNOWN};
 BOOLEAN   mFirstEnterLegacyForm = FALSE;
 
@@ -1484,11 +1484,11 @@ LegacyBootMaintUiLibDestructor (
   IN EFI_SYSTEM_TABLE  *SystemTable
   )
 {
   EFI_STATUS    Status;
 
-  if (mLegacyBootOptionPrivate->DriverHandle != NULL) {
+  if (mLegacyBootOptionPrivate != NULL && mLegacyBootOptionPrivate->DriverHandle != NULL) {
     Status = gBS->UninstallMultipleProtocolInterfaces (
                     mLegacyBootOptionPrivate->DriverHandle,
                     &gEfiDevicePathProtocolGuid,
                     &mLegacyBootOptionHiiVendorDevicePath,
                     &gEfiHiiConfigAccessProtocolGuid,
-- 
1.9.5.msysgit.1