NFA API: Remove unused scratch ptr from struct mq

unit/internal/lbr.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, Intel Corporation
+ * Copyright (c) 2015-2016, Intel Corporation
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -120,7 +120,6 @@ protected:
         q.length = 0; // filled in by test
         q.history = nullptr;
         q.hlength = 0;
-        q.scratch = nullptr; // not needed by LBR
         q.report_current = 0;
         q.cb = onMatch;
         q.som_cb = nullptr; // only used by Haig