Add langid to example cdc_msc.

Signed-off-by: Chang Feng <chang_196700@hotmail.com>

examples/device/cdc_msc/src/usb_descriptors.c

@@ -155,8 +155,10 @@ static uint16_t _desc_str[32];
 
 // Invoked when received GET STRING DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
-uint16_t const* tud_descriptor_string_cb(uint8_t index)
+uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
 {
+  (void) langid;
+
   uint8_t chr_count;
 
   if ( index == 0)