[compiler-rt] Fix flaky test xray/basic-filtering.cpp (PR #186611)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 commented:

It's unclear why this fixes the issue.

And if you have reproduced this locally and this makes the frequency of failure much lower, this is still only a bandaid fix. We shouldn't be relying on timing in the first place to ensure a test passes.

https://github.com/llvm/llvm-project/pull/186611