add while loop to usbd task to run until task queue is empty

src/device/usbd.c

@@ -265,6 +265,9 @@ static tusb_error_t usbd_main_st(void)
 
   OSAL_SUBTASK_BEGIN
 
+  // Loop until there is no more events in the queue
+  while (1)
+  {
     tusb_error_t err;
     err = TUSB_ERROR_NONE;
 
@@ -305,6 +308,7 @@ static tusb_error_t usbd_main_st(void)
     {
       STASK_ASSERT(false);
     }
+  }
 
   OSAL_SUBTASK_END
 }