hcd/ehci: hcd_edpt_open() return false if ep is already opened. implement hcd_edpt_close()

src/host/usbh.c

@@ -520,7 +520,7 @@ void tuh_task_ext(uint32_t timeout_ms, bool in_isr) {
   // Loop until there is no more events in the queue
   while (1) {
     hcd_event_t event;
-    if (!osal_queue_receive(_usbh_q, &event, timeout_ms)) return;
+    if (!osal_queue_receive(_usbh_q, &event, timeout_ms)) { return; }
 
     switch (event.event_id) {
       case HCD_EVENT_DEVICE_ATTACH: