x86/asm/boot: Fix path in comments

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Cc: Martin Mares <mj@ucw.cz>
Link: http://lkml.kernel.org/r/1422382588-10367-1-git-send-email-kuleshovmail@gmail.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>