SLUB: slabinfo upgrade

-e Show empty slabs
-d Modification of slab debug options at runtime
-o Operations. Display of ctor / dtor etc.
-r Report: Display all available information about a slabcache.

Cleanup tracking display and make it work right.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>