Revert "nohz: Fix another inconsistency between CONFIG_NO_HZ=n and nohz=off"

This reverts commit 3b3a3b12979914bdc55c05ad0e5f189defd9c3ee.
Revert "mm: kmemleak: avoid false negatives on vmalloc'ed objects"

This reverts commit 19e824331aee344b0e12541ee03689ddb0f3c4e5.