Re: [libvirt] [PATCH 2/2] Fix reference handling leak on qemuMonitor

The current code pattern requires that callers of qemuMonitorClose check for the return value == 0, and if so, set priv->mon = NULL and release the reference held on the associated virDomainObjPtr The change d84bb6d6a3bd2fdd530184cc9743249ebddbee71 violated that requirement, meaning that priv->mon never gets set to NULL, and a reference count is leaked on virDomainObjPtr. This design was a bad one, so remove the need to check the return valueof qemuMonitorClose(). Instead allow registration of a callback that's invoked just when the last reference on qemuMonitorPtr is released. Finally there was a potential reference leak in qemuConnectMonitor in the failure path.