Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core/locking changes for v3.4 from Ingo Molnar

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Simplify return logic
  futex: Cover all PI opcodes with cmpxchg enabled check