net: simplify interfaceTable for BSD variants

This change drops parseInterfaceTable which becomes unnecessary by the
golang.org/x/net/route plumbing.

Change-Id: I05f96e347de950bb1e9292bb3eeff01bb40e292f
Reviewed-on: https://go-review.googlesource.com/23125
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/net/interface_bsd.go

@@ -20,10 +20,6 @@ func interfaceTable(ifindex int) ([]Interface, error) {
 	if err != nil {
 		return nil, err
 	}
-	return parseInterfaceTable(ifindex, msgs)
-}
-
-func parseInterfaceTable(ifindex int, msgs []route.Message) ([]Interface, error) {
 	n := len(msgs)
 	if ifindex != 0 {
 		n = 1