staging/lustre: Move /proc/fs/lustre root level files to sysfs

except devices, for now.

Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Dmitry Eremin <dmitry.eremin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>