add desc_audio_control to midi descriptor callback

examples/host/midi_rx/src/main.c

@@ -106,8 +106,8 @@ void tuh_midi_rx_cb(uint8_t idx, uint32_t num_packets) {
     return;
   }
 
-  uint8_t cable_num;
   uint8_t buffer[48];
+  uint8_t cable_num = 0;
   uint32_t bytes_read = tuh_midi_stream_read(idx, &cable_num, buffer, sizeof(buffer));
 
   printf("Cable %u rx %lu bytes: ", cable_num, bytes_read);

examples/host/midi_rx/src/tusb_config.h

@@ -111,8 +111,6 @@ extern "C" {
 #define CFG_TUH_DEVICE_MAX          (3*CFG_TUH_HUB + 1)
 #define CFG_TUH_MIDI                CFG_TUH_DEVICE_MAX
 
-#define CFG_MIDI_HOST_DEVSTRINGS 1
-
 #ifdef __cplusplus
 }
 #endif