domain_conf: fix crash in virDomainObjListFindByUUIDInternal

If a domain object is being removed and looked up concurrently we must
ensure we unlock the object before unreferencing it, since the latter
might free the object.

The flaw was introduced in commit feb1a4d792.

Signed-off-by: Michael Chapman <mike@very.puzzling.org>

src/conf/domain_conf.c

@@ -1068,9 +1068,9 @@ virDomainObjListFindByUUIDInternal(virDomainObjListPtr doms,
     if (obj) {
         virObjectLock(obj);
         if (obj->removing) {
+            virObjectUnlock(obj);
             if (ref)
                 virObjectUnref(obj);
-            virObjectUnlock(obj);
             obj = NULL;
         }
     }