Remove unreachable callback

src/class/dfu/dfu_mode_device.c

@@ -590,14 +590,4 @@ static bool dfu_mode_state_machine(uint8_t rhport, tusb_control_request_t const
 }
 
 
-bool dfu_mode_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes)
-{
-  (void) rhport;
-  (void) ep_addr;
-  (void) result;
-  (void) xferred_bytes;
-  return true;
-}
-
-
  #endif

src/class/dfu/dfu_mode_device.h

@@ -122,7 +122,6 @@ void     dfu_mode_init(void);
 void     dfu_mode_reset(uint8_t rhport);
 uint16_t dfu_mode_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t max_len);
 bool     dfu_mode_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t const * request);
-bool     dfu_mode_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes);
 
 
 #ifdef __cplusplus

src/device/usbd.c

@@ -194,7 +194,7 @@ static usbd_class_driver_t const _usbd_driver[] =
     .reset            = dfu_mode_reset,
     .open             = dfu_mode_open,
     .control_xfer_cb  = dfu_mode_control_xfer_cb,
-    .xfer_cb          = dfu_mode_xfer_cb,
+    .xfer_cb          = NULL,
     .sof              = NULL
   },
   #endif