sched: Convert pi_lock to raw_spinlock

Convert locks which cannot be sleeping locks in preempt-rt to
raw_spinlocks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Ingo Molnar <mingo@elte.hu>

kernel/rtmutex-debug.c

@@ -37,8 +37,8 @@ do {								\
 	if (rt_trace_on) {					\
 		rt_trace_on = 0;				\
 		console_verbose();				\
-		if (spin_is_locked(&current->pi_lock))		\
-			spin_unlock(&current->pi_lock);		\
+		if (raw_spin_is_locked(&current->pi_lock))	\
+			raw_spin_unlock(&current->pi_lock);	\
 	}							\
 } while (0)