bootmem: clean up bootmem.c file header

/*

 *  linux/mm/bootmem.c

 *  bootmem - A boot-time physical memory allocator and configurator

 *

 *  Copyright (C) 1999 Ingo Molnar

 *  Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999

 *                1999 Kanoj Sarcar, SGI

 *                2008 Johannes Weiner

 *

 *  simple boot-time physical memory area allocator and

 *  free memory collector. It's used to deal with reserved

 *  system memory and memory holes as well.

 * Access to this subsystem has to be serialized externally (which is true

 * for the boot process anyway).

 */

#include <linux/init.h>

#include <linux/pfn.h>

#include "internal.h"

/*

 * Access to this subsystem has to be serialized externally. (this is

 * true for the boot process anyway)

 */

unsigned long max_low_pfn;

unsigned long min_low_pfn;

unsigned long max_pfn;