x86: unify strings in arch/x86/boot/compressed/misc_??.c

There seems to be a preference for the 64 bit version so use that on 32 bit and
drop the stray leading "."

Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>