sched/core: Simplify preempt_count tests

Since we stopped setting PREEMPT_ACTIVE, there is no need to mask it
out of preempt_count() tests.

Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
Reviewed-by: Thomas Gleixner <[e-mail]>
Reviewed-by: Steven Rostedt <[e-mail]>
Reviewed-by: Frederic Weisbecker <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Mike Galbraith <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: [e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

include/linux/preempt.h

···
  * Check whether we were atomic before we did preempt_disable():
  * (used by the scheduler)
  */
-#define in_atomic_preempt_off() \
-		((preempt_count() & ~PREEMPT_ACTIVE) != PREEMPT_DISABLE_OFFSET)
+#define in_atomic_preempt_off() (preempt_count() != PREEMPT_DISABLE_OFFSET)
 
 #if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER)
 extern void preempt_count_add(int val);

kernel/sched/core.c

···
 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
 static inline int preempt_count_equals(int preempt_offset)
 {
-	int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth();
+	int nested = preempt_count() + rcu_preempt_depth();
 
 	return (nested == preempt_offset);
 }