Fixes comment style.
Added names to return parameters to clarify what they are.

Change-Id: Ib6f7f58b36981e08b63de1a4cd582ce99cfb4519
Reviewed-on: https://go-review.googlesource.com/107235Reviewed-by: Iskander Sharipov <iskander.sharipov@intel.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>