x86: properly __init-annotate recent early_printk additions

Impact: cleanup, save memory

Don't keep code resident that's only needed during startup.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <49B91103.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>