& modify some comment in rt_usb_device_init git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2346 bbd45198-f89e-11dd-88c7-29a3b14d5316
git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2344 bbd45198-f89e-11dd-88c7-29a3b14d5316