remove unused code in _set_interface

& modify some comment in rt_usb_device_init

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2346 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/drivers/usb/usbdevice/core/core.c

@@ -221,9 +221,6 @@ static rt_err_t _set_interface(struct udevice* device, ureq_t setup)
 
     RT_DEBUG_LOG(RT_DEBUG_USB, ("_set_interface\n"));
 
-    setup->index & 0xFF;
-    setup->value & 0xFF;
-
     /* find the specified interface */
     intf = rt_usbd_find_interface(device, setup->index & 0xFF);
 

components/drivers/usb/usbdevice/core/usbdevice.c

@@ -69,7 +69,7 @@ rt_err_t rt_usb_device_init(const char* udc_name)
     /* set device descriptor to the device */
     rt_usbd_device_set_descriptor(udevice, cls->dev_desc);
 
-    /* add the mass storage class to the configuration */
+    /* add the class to the configuration */
     rt_usbd_config_add_class(cfg, cls);
     
     /* add the configuration to the device */