Allow swsusp to freeze processes successfully under heavy load by freezing
userspace processes before kernel threads.

[Thanks to Nigel Cunningham <nigel@suspend2.net> for suggesting the
way to go.]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>