staging: lustre: obdclass: Make structure declerations static const

staging: lustre: obdclass: Make structure declerations static const

obd_device_list_sops and obd_device_list_fops are not referenced
outside of linux-module.c, and in the general use case
struct file_operations and struct seq_operations should be a const
object, so make them static and const.

This patch fixes the following sparse warnings:
WARNING: struct seq_operations should normally be const
WARNING: struct file_operations should normally be const

Signed-off-by: Cihangir Akturk <cakturk@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>