Made ConnPool::returnConn() private

rdbms/ConnPool.hpp

@@ -55,6 +55,10 @@ public:
    */
   PooledConn getConn();
 
+private:
+
+  friend PooledConn;
+
   /**
    * Calls commit on the specified database connection and returns it to the
    * pool.
@@ -63,8 +67,6 @@ public:
    */
   void returnConn(Conn *const conn);
 
-private:
-
   /**
    * The database connection factory.
    */