Revert "fix build"

This reverts commit 3f09071d2a2ca5a83edaec57bf200b4d1c28faf5.
Revert "Squash a lot of slab, slob and slub commits from Faux123"

This reverts commit 6b359def9f5e109c86941978161ab026c903a0d0.
workqueue: proper fix for -O3 optimization

Conflicts:
	kernel/workqueue.c