eio/fallback: mark all fallback monitors as fallbacks, not just for win32

@fix

Differential Revision: https://phab.enlightenment.org/D6443

src/lib/eio/eio_monitor_poll.c

@@ -328,6 +328,7 @@ eio_monitor_fallback_add(Eio_Monitor *monitor)
    backend->children = eina_hash_string_superfast_new(free);
    backend->parent = monitor;
    monitor->backend = backend;
+   monitor->fallback = EINA_TRUE;
    backend->work = ecore_thread_run(_eio_monitor_fallback_heavy_cb,
                                     _eio_monitor_fallback_end_cb,
                                     _eio_monitor_fallback_cancel_cb,

src/lib/eio/eio_monitor_win32.c

@@ -403,7 +403,6 @@ void eio_monitor_backend_add(Eio_Monitor *monitor)
    free(backend);
  fallback:
    INF("falling back to poll monitoring");
-   monitor->fallback = EINA_TRUE;
    eio_monitor_fallback_add(monitor);
 }