proc: move /proc/slabinfo boilerplate to mm/slub.c, mm/slab.c

Lose dummy ->write hook in case of SLUB, it's possible now.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
4 files changed