bootmem: clean up bootmem.c file header

Change the description, move a misplaced comment about the allocator
itself and add me to the list of copyright holders.
Signed-off-by: NJohannes Weiner <hannes@saeurebad.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/bootmem.c

 /*
- *  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>
@@ -19,10 +19,6 @@
 
 #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;