修复 undo recycler线程cpu占用100%

src/gausskernel/storage/access/ustore/undo/knl_uundorecycle.cpp

@@ -448,7 +448,9 @@ static void RecycleWaitIfNotUsed()
 #endif
         ) {
         uint64 nonRecycled = 0;
-        while (true) {
+        while (g_instance.attr.attr_storage.undo_zone_count == 0) {
+            /* Clear any already-pending wakeups */
+            ResetLatch(&t_thrd.proc->procLatch);
             if (t_thrd.undorecycler_cxt.shutdown_requested) {
                 ereport(LOG, (errmodule(MOD_UNDO), errmsg(UNDOFORMAT("UndoRecycler: shutting down"))));
                 ResourceOwnerRelease(t_thrd.utils_cxt.CurrentResourceOwner, RESOURCE_RELEASE_BEFORE_LOCKS, false, true);