x86: remove over noisy debug printk

pageattr-test.c contains a noisy debug printk that people reported.
The condition under which it prints (randomly tapping into a mem_map[]
hole and not being able to c_p_a() there) is valid behavior and not
interesting to report.

Remove it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>