Add pointer check for NULL before dereference it.

Signed-off-by: sfu5
Reviewed-by: tye

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12537 6f19259b-4bc3-4df7-8a09-765794883524

SecurityPkg/VariableAuthenticated/EsalVariableDxeSal/Variable.c

@@ -846,6 +846,7 @@ UpdateVariableCache (
           // If size of data changes, allocate pool and copy data.
           //
           Entry->Data = AllocatePool (DataSize);
+          ASSERT (Entry->Data != NULL);
           Entry->DataSize = DataSize;
           CopyMem (Entry->Data, Data, DataSize);
         }