The per cpu schedule counters need to be summed up over all possible cpus. 
When testing hotplug cpu remove I saw the sum of the online cpu count for
nr_uninterruptible go negative which made the load average go nuts.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>