runtime: decrement netpollWaiters in netpollunblock
We used to decrement it in netpollgoready, but that missed
the common case of a descriptor becoming ready due to I/O.
All calls to netpollgoready go through netpollunblock,
so this shouldn't miss any decrements we missed before.
Fixes #60782
Change-Id: Ideefefa1ac96ca38e09fe2dd5d595c5dd7883237
Reviewed-on: https://go-review.googlesource.com/c/go/+/503923
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com>
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Run-TryBot: Ian Lance Taylor <iant@google.com> Reviewed-by: Michael Knyszek <mknyszek@google.com>
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