Remove unused 'struct route' fields.


git-svn-id: svn+ssh://svn.freebsd.org/base/head@274315 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Remove unused 'struct route *' argument from nd6_output_flush().


git-svn-id: svn+ssh://svn.freebsd.org/base/head@274316 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f