[riscv64] Add check_fn before calculating the expected value

Change-Id: I4b83907b735994a729b57b9c4a75d3672ce78b15
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3482916Reviewed-by: ji qiu <qiuji@iscas.ac.cn>
Auto-Submit: Yahan Lu <yahan@iscas.ac.cn>
Reviewed-by: Yahan Lu <yahan@iscas.ac.cn>
Commit-Queue: Yahan Lu <yahan@iscas.ac.cn>
Cr-Commit-Position: refs/heads/main@{#79218}