monitor/qmp: Update comment for commit 4eaca8de268

Commit 4eaca8de268 dropped monitor_qmp_respond()'s parameter @id
without updating its function comment.  Fix that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190816193305.12090-1-armbru@redhat.com>

monitor/qmp.c

@@ -97,7 +97,7 @@ void qmp_send_response(MonitorQMP *mon, const QDict *rsp)
 }
 
 /*
- * Emit QMP response @rsp with ID @id to @mon.
+ * Emit QMP response @rsp to @mon.
  * Null @rsp can only happen for commands with QCO_NO_SUCCESS_RESP.
  * Nothing is emitted then.
  */