FW driver has to be explicitly closed.

git-svn-id: http://subversion.jackaudio.org/jack/jack2/trunk/jackmp@4271 0c269be4-1314-0410-8aa9-9f06e86f4224

common/JackServer.cpp

@@ -137,6 +137,7 @@ int JackServer::Close()
     fChannel.Close();
     fAudioDriver->Detach();
     fAudioDriver->Close();
+    fFreewheelDriver->Close();
     fEngine->Close();
     // TODO: move that in reworked JackServerGlobals::Destroy()
     JackMessageBuffer::Destroy();