Remove ASSERT when failed to Get/Set “AttemptOrder” and “ClientId” variable.

Removes RT attribute for “AttemptOrder” variable.
Signed-off-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Dong, Guo <guo.dong@intel.com>
Reviewed-by: Yao, Jiewen <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15328 6f19259b-4bc3-4df7-8a09-765794883524

NetworkPkg/Dhcp6Dxe/Dhcp6Utility.c

@@ -1,7 +1,7 @@
 /** @file
   Dhcp6 support functions implementation.
 
-  Copyright (c) 2009 - 2012, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2009 - 2014, 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
@@ -157,7 +157,10 @@ Dhcp6GenerateClientId (
                   Duid->Length + 2,
                   (VOID *) Duid
                   );
-  ASSERT_EFI_ERROR (Status);
+  if (EFI_ERROR (Status)) {
+    FreePool (Duid);
+    return NULL;
+  }
 
   return Duid;
 }