[patch for-3.14] mm, slub: list_lock may not be held in some circumstances

Commit c65c1877bd68 ("slub: use lockdep_assert_held") incorrectly required that add_full() and remove_full() hold n->list_lock. The lock is only taken when kmem_cache_debug(s), since that's the only time it actually does anything. Require that the lock only be taken under such a condition.

[patch for-3.14] mm, slub: list_lock may not be held in some circumstances

Commit c65c1877bd68 (slub: use lockdep_assert_held) incorrectly required that add_full() and remove_full() hold n-list_lock. The lock is only taken when kmem_cache_debug(s), since that's the only time it actually does anything. Require that the lock only be taken under such a condition.