runtime: call osyield directly in lockextra
The `yield := osyield` line doesn't serve any purpose, it's committed in `2015`, time to delete that line:)
Change-Id: I382d4d32cf320f054f011f3b6684c868cbcb0ff2
GitHub-Last-Rev:
7a0aa25e555edd901add25a1101e7b145d1f3bd8
GitHub-Pull-Request: golang/go#36078
Reviewed-on: https://go-review.googlesource.com/c/go/+/210837
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>