[PATCH] cpuset: task_lock comment fix

Fix cpuset comment involving case of a tasks cpuset pointer being NULL.
Thanks to "the_top_cpuset_hack", this code no longer sees NULL task->cpuset
pointers.

Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>