bug#18040 - ndb - online build of unique index

  Make sure that senderData value in communiation with LQH does not get overwritten by incorrect union
  

storage/ndb/src/kernel/blocks/suma/Suma.hpp

@@ -239,7 +239,8 @@ public:
       suma.progError(line, cause, extra); 
     }
     
-    union { Uint32 nextPool; Uint32 nextList; Uint32 prevList; Uint32 ptrI; };
+    Uint32 prevList; Uint32 ptrI;
+    union { Uint32 nextPool; Uint32 nextList; };
   };
   friend struct SyncRecord;