vfs/file: add reference counting to prevent accidental close during reading writing...

Signed-off-by: Shoukui Zhang <zhangshoukui@xiaomi.com>

audio/audio.c

@@ -603,6 +603,7 @@ static int audio_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
         {
           audinfo("AUDIOIOC_UNREGISTERMQ\n");
 
+          fs_putfilep(upper->usermq);
           upper->usermq = NULL;
           ret = OK;
         }