Fix for compiler warnings and errors.

git-svn-id: svn://localhost/ardour2/trunk@1547 d708f5d6-7413-0410-9779-e7cbd77b26cf

libs/ardour/audioengine.cc

@@ -225,9 +225,9 @@ AudioEngine::jack_sync_callback (jack_transport_state_t state, jack_position_t*
 {
 	if (_jack && session) {
 		return session->jack_sync_callback (state, pos);
-	} else {
-		return true;
 	}
+
+	return true;
 }
 
 int

libs/pbd/pbd/rcu.h

@@ -25,7 +25,7 @@ class RCUManager
   protected:
 	union {
 	    boost::shared_ptr<T>* m_rcu_value;
-	    volatile gpointer gptr;
+	    mutable volatile gpointer gptr;
 	} x;
 };