internal/netreflect: fix test on NaCl and Plan 9

Change-Id: Ia8bc87d0398951d7be74779279dca177f499d293
Reviewed-on: https://go-review.googlesource.com/36377
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
1 file changed