[super property speed] js-perf-test: minor formatting fix

Bug: v8:9237
Change-Id: Iaa1e3485eaecdd5af654177f207a990a2e63396b
No-Try: True
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2374545Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69546}