This makes it possible to preserve basic futex support and compile out the
PI support when RT mutexes are not available.
Signed-off-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <dvhart@infradead.org>
Link: http://lkml.kernel.org/r/alpine.LFD.2.20.1708010024190.5981@knanqh.ubzr