[RFC PATCH v3 3/7] hq-spinlock: add contention detection

[WEI-HONG, YE]

Hi,

I may be missing something, but this patch adds
`update_counters_qspinlock()` for remote handoff accounting.

I tried commenting it out locally, and the kernel still built successfully
with `CONFIG_HQSPINLOCKS=y` and `CONFIG_HQSPINLOCKS_DEBUG=y`. I also could
not find a call site for it in the series, so it looks like this helper may
currently be unreferenced.

Is it still needed, or was the call site possibly missed in this RFC version?

Cheers,
Hong