aio_cancel need signal caller after the succeed and fix minor issue in the error handler

fs/aio/aio_initialize.c

@@ -109,6 +109,7 @@ void aio_initialize(void)
   /* Initialize counting semaphores */
 
   (void)nxsem_init(&g_aioc_freesem, 0, CONFIG_FS_NAIOC);
+  (void)nxsem_setprotocol(&g_aioc_freesem, SEM_PRIO_NONE);
   (void)nxsem_init(&g_aio_exclsem, 0, 1);
 
   g_aio_holder = INVALID_PROCESS_ID;