route: avoid unnecessary type conversions
route: avoid unnecessary type conversions

CL generated mechanically with github.com/mdempsky/unconvert.

Change-Id: I22eea0b991462dd00f3fa28073a8b886e19bc068
Reviewed-on: https://go-review.googlesource.com/100095
Run-TryBot: Kunpei Sakai <16e6eef4865510c955b62d2536a11db5146a1308@gmail.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Alberto Donizetti <90b16103a35511ced020676f3544f17117fb4c92@gmail.com>

golang/net