kUnkown -> kUnknown

Bug: chromium:1110816
Change-Id: I8138df76ade7f2a78632e329682cca83c64edac8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2407776
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Auto-Submit: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69875}