x86: use smp_call_function_single() in arch/x86/kernel/cpu/mcheck/mce_amd_64.c

Attempting to rid us of the problematic work_on_cpu().  Just use
smp_call_function_single() here.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <20090318042217.EF3F1DDF39@ozlabs.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>