This is to fix issue in [this log](https://github.com/apache/nuttx/actions/runs/9173629303/job/25222879619):
```
Configuration/Tool: esp32c3-generic/twai esp32c6-devkitm/twai esp32c6-devkitc/twai esp32h2-devkit/twai
Error: common/espressif/esp_twai.c:242:7: error: variable 'ret' set but not used [-Werror=unused-but-set-variable]
```
Signed-off-by: Yanfeng Liu <yfliu2008@qq.com>