- fix compatibility with tools/perf/builtin-record.c in upstream kernel

The patch is against 2.6.30 and is tested on intel and ppc architectures.

ChangeLog:
 20. Jan 2009 V0.1
  - First Version for Kernel 2.6.28.1
 31. Mar 2009 V0.2
  - Ported to Kernel 2.6.29
 03. Jun 2009 V0.3
  - Ported to Kernel 2.6.30
  - Redesigned what was suggested by Ingo Molnar
  - the thread watch monitor is gone
  - the /proc/stackmon entry is also gone
  - slim down
 04. Jun 2009 V0.4
  - Redesigned everything that was suggested by Andrew Morton
  - slim down
 04. Jun 2009 V0.5
  - Code cleanup
 06. Jun 2009 V0.6
  - Fix missing mm->mmap_sem locking in function task_show_stack_usage()
  - Code cleanup
 10. Jun 2009 V0.7
  - update Documentation/filesystem/proc.txt
 10. Jun 2009 V0.8
  - change maps/smaps output, displays now the max. stack size
 24. Jun 2009 V0.9
  - use walk_page_range() to determinate the stack usage high water mark
  - include swapped pages to the stack usage high water mark count
 24. Jun 2009 V0.10
  - fix off by one bug
  - cleanup

 fs/exec.c                          |    2
 include/linux/sched.h              |    1
 kernel/fork.c                      |    2
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>