Staging: lustre: lnet: Make functions static

This patch makes functions proc_lnet_routes, proc_lnet_routers,
proc_lnet_peers and proc_lnet_nis static in file router_proc.c
as they are used only in this file.

This problem is detected by sparse.

Signed-off-by: Vaishali Thakkar <vthakkar1994@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>