migration: finalize current_migration object

current_migration has .instance_finalize callback, but it is not
called, because nobody unrefs current_migration. Fix that.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

include/migration/misc.h

@@ -44,6 +44,7 @@ void dump_vmstate_json_to_file(FILE *out_fp);
 
 /* migration/migration.c */
 void migration_object_init(void);
+void migration_object_finalize(void);
 void qemu_start_incoming_migration(const char *uri, Error **errp);
 bool migration_is_idle(void);
 void add_migration_state_change_notifier(Notifier *notify);

migration/migration.c

@@ -132,6 +132,11 @@ void migration_object_init(void)
     }
 }
 
+void migration_object_finalize(void)
+{
+    object_unref(OBJECT(current_migration));
+}
+
 /* For outgoing */
 MigrationState *migrate_get_current(void)
 {

vl.c

@@ -4792,6 +4792,7 @@ int main(int argc, char **argv, char **envp)
     monitor_cleanup();
     qemu_chr_cleanup();
     user_creatable_cleanup();
+    migration_object_finalize();
     /* TODO: unref root container, check all devices are ok */
 
     return 0;