fix warnings

examples/host/cdc_msc_hid/src/hid_app.c

@@ -217,6 +217,8 @@ static void process_mouse_report(hid_mouse_report_t const * report)
 //--------------------------------------------------------------------+
 static void process_generic_report(uint8_t dev_addr, uint8_t instance, uint8_t const* report, uint16_t len)
 {
+  (void) dev_addr;
+
   uint8_t const rpt_count = hid_info[instance].report_count;
   tuh_hid_report_info_t* rpt_info_arr = hid_info[instance].report_info;
   tuh_hid_report_info_t* rpt_info = NULL;