[PATCH] MdePkg DxeHstiLib: Fix ErrorString pointer incorrectly calculated

[Star Zeng <star.zeng@intel.com>]

Fix ErrorString pointer is incorrectly calculated in
InternalHstiIsValidTable().

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Star Zeng <star.zeng@intel.com>
---
 MdePkg/Library/DxeHstiLib/HstiDxe.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/MdePkg/Library/DxeHstiLib/HstiDxe.c b/MdePkg/Library/DxeHstiLib/HstiDxe.c
index 58510766bb43..d08d8def0cb5 100644
--- a/MdePkg/Library/DxeHstiLib/HstiDxe.c
+++ b/MdePkg/Library/DxeHstiLib/HstiDxe.c
@@ -1,6 +1,6 @@
 /** @file
 
-  Copyright (c) 2015 - 2017, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2015 - 2018, Intel Corporation. All rights reserved.<BR>
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
   which accompanies this distribution.  The full text of the license may be found at
@@ -211,7 +211,7 @@ InternalHstiIsValidTable (
   }
 
   ErrorStringSize = HstiSize - sizeof(ADAPTER_INFO_PLATFORM_SECURITY) - Hsti->SecurityFeaturesSize * 3;
-  ErrorString = (CHAR16 *)((UINTN)Hsti + sizeof(ADAPTER_INFO_PLATFORM_SECURITY) - Hsti->SecurityFeaturesSize * 3);
+  ErrorString = (CHAR16 *)((UINTN)Hsti + sizeof(ADAPTER_INFO_PLATFORM_SECURITY) + Hsti->SecurityFeaturesSize * 3);
 
   //
   // basic check for ErrorString
-- 
2.13.3.windows.1