Updated slub.c to upstream

Based on
https://github.com/Christopher83/samsung-kernel-msm7x30/commit/41418b88d6de4994e0a4d5cbf3d3ee9d290fe236
and
https://github.com/Christopher83/samsung-kernel-msm7x30/commit/10e9d060079a2453c6ac2b71632627394ba20431