x86: clean up output resulting from update_mptable option

Impact: cleanup

Without apic=verbose, using the update_mptable option would result in
garbled and confusing output due to the inconsistent use of printk() vs
apic_printk().

Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <49B914B6.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>