openvz: unlock virDomainObj objects in openvzOpen

openvzOpen fucntion must leave unlocked virDomainObj objects in
driver->domains.

Now even simple commands like list or domain lookup hang,
for example virsh -c openvz:///system list --all.

Signed-off-by: Dmitry Guryanov <dguryanov@parallels.com>

src/openvz/openvz_conf.c

@@ -673,6 +673,7 @@ int openvzLoadDomains(struct openvz_driver *driver) {
             goto cleanup;
         }
 
+        virDomainObjUnlock(dom);
         dom = NULL;
     }