x86, apic: Use register_lapic_address() in init_apic_mapping()

Remove the printk as well, we don't want to print when nothing
changed. We print in register_lapic_address() already.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
LKML-Reference: <4CFDF68A.7020902@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>