x86, mce: Add __cpuinit to hotplug callback functions

The mce_disable_cpu() and mce_reenable_cpu() are called only
from mce_cpu_callback() which is marked as __cpuinit.
So these functions can be __cpuinit too.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Andi Kleen <ak@linux.intel.com>
LKML-Reference: <4B0E3C4E.4090809@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>