internal/netreflect: fix test on nacl, plan9 and windows

Change-Id: Ia274e47affd5fc2b9bdea077fa8043887044d0ec
Reviewed-on: https://go-review.googlesource.com/28110
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