runtime: fix typo in debuglog comment
runtime: fix typo in debuglog comment

Change-Id: I8a40461b93eab034ed930e0c5e32391f84cdbc5a
Reviewed-on: https://go-review.googlesource.com/c/go/+/170799
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
Reviewed-by: Sebastien Binet <e007d926a61a64a3456bccd7b023e55740ae3e6a@gmail.com>

akutz/go,nawawi/go,josharian/go,josharian/go,cloudflare/go,CAFxX/go,josharian/go,akutz/go,CAFxX/go,golang/go,cloudflare/go,CAFxX/go,nawawi/go,golang/go,nawawi/go,akutz/go,akutz/go,CAFxX/go,cloudflare/go,nawawi/go,nawawi/go,josharian/go,golang/go,akutz/go,akutz/go,cloudflare/go,nawawi/go,josharian/go,josharian/go,CAFxX/go,golang/go,cloudflare/go,golang/go,cloudflare/go,cloudflare/go,josharian/go,golang/go,josharian/go,golang/go,cloudflare/go,golang/go,nawawi/go,nawawi/go,akutz/go,akutz/go,CAFxX/go,CAFxX/go,CAFxX/go