x86: fix duplicated sysfs attribute

The sysfs attribute cmci_disabled was accidentall turned into a
duplicate of ignore_ce, breaking all other attributes.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>