ipv6: simplify init function for darwin

Change-Id: If0bcd08de56518ec1dd79476bc37e276ae550d47
Reviewed-on: https://go-review.googlesource.com/28998
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