[jreed-doxygen] fix doxygen warning

fix no matching class member found

src/lib/cc/session.cc

@@ -254,7 +254,8 @@ SessionImpl::internalRead(const asio::error_code& error,
     }
 }
 
-Session::Session(io_service& io_service) : impl_(new SessionImpl(io_service))
+Session::Session(asio::io_service& io_service) :
+    impl_(new SessionImpl(io_service))
 {}
 
 Session::~Session() {