staging/lustre/obdclass: Move AT controls from sysctl to sysfs

Adaptive Timeouts controls are being moved from /proc/sys/lustre
to /sys/fs/lustre

Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>