csw structure address alignment

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2468 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/drivers/usb/usbdevice/class/mstorage.c

@@ -30,6 +30,7 @@ static uep_t ep_in, ep_out;
 static rt_uint8_t *buffer;
 static rt_uint8_t *write_ptr;
 static int status = STATUS_CBW;
+ALIGN(RT_ALIGN_SIZE)
 static struct ustorage_csw csw;
 static rt_device_t disk;
 static rt_uint32_t _block;