qemu: turn qemuDomainObjExitMonitor into void

This reverts my
    commit dc2fd51fd727bbb6de172e0ca4b7dd307bb99180
    Check for domain liveness in qemuDomainObjExitMonitor
which fixed the symptoms of the bug later fixed by
    commit 81f50cb92d16643bcd749e3ab5b404b8b7cec643
    qemu: Avoid calling qemuProcessStop without a job

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

src/qemu/THREADS.txt

@@ -170,11 +170,6 @@ To acquire the QEMU monitor lock
     - Acquires the virDomainObj *lock
 
   These functions must not be used by an asynchronous job.
-  Note that the virDomainObj is unlocked during the time in
-  monitor and it can be changed, e.g. if QEMU dies, qemuProcessStop
-  may free the live domain definition and put the persistent
-  definition back in vm->def. The callers should check the return
-  value of ExitMonitor to see if the domain is still alive.
 
 
 To acquire the QEMU monitor lock as part of an asynchronous job

src/qemu/qemu_domain.c

@@ -5893,24 +5893,11 @@ void qemuDomainObjEnterMonitor(virQEMUDriver *driver,
 /* obj must NOT be locked before calling
  *
  * Should be paired with an earlier qemuDomainObjEnterMonitor() call
- *
- * Returns -1 if the domain is no longer alive after exiting the monitor.
- * In that case, the caller should be careful when using obj's data,
- * e.g. the live definition in vm->def has been freed by qemuProcessStop
- * and replaced by the persistent definition, so pointers stolen
- * from the live definition could no longer be valid.
  */
-int qemuDomainObjExitMonitor(virQEMUDriver *driver,
+void qemuDomainObjExitMonitor(virQEMUDriver *driver,
                               virDomainObj *obj)
 {
     qemuDomainObjExitMonitorInternal(driver, obj);
-    if (!virDomainObjIsActive(obj)) {
-        if (virGetLastErrorCode() == VIR_ERR_OK)
-            virReportError(VIR_ERR_OPERATION_FAILED, "%s",
-                           _("domain is no longer running"));
-        return -1;
-    }
-    return 0;
 }
 
 /*

src/qemu/qemu_domain.h

@@ -487,7 +487,7 @@ qemuMonitor *qemuDomainGetMonitor(virDomainObj *vm)
 void qemuDomainObjEnterMonitor(virQEMUDriver *driver,
                                virDomainObj *obj)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
-int qemuDomainObjExitMonitor(virQEMUDriver *driver,
+void qemuDomainObjExitMonitor(virQEMUDriver *driver,
                               virDomainObj *obj)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
 int qemuDomainObjEnterMonitorAsync(virQEMUDriver *driver,