qemu: Print better warning in qemuAgentNotifyEvent

We have this function qemuAgentNotifyEvent() which is supposed to
be called from thread pool responsible for processing qemu
monitor events. The function then should wake up other thread
that is waiting for a guest to shutdown or reboot. However, if we
have received a different error a warning is printed out. This
warning lacks info on which event is expected.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_agent.c

@@ -1241,7 +1241,8 @@ void qemuAgentNotifyEvent(qemuAgentPtr mon,
         }
     } else {
         /* shouldn't happen but one never knows */
-        VIR_WARN("Received unexpected event %d", event);
+        VIR_WARN("Received unexpected event %d (expected %d)",
+                 event, mon->await_event);
     }
 }