Revert "scheduler: SCHEDULER_EXIT_FUNCTION() is not needed"

This reverts commit 667617ad043a4587d8d366d5192d9ad291cfa37a.

Scheduler profiler uses CPU local data to store function information, hence
arch_thread_context_switch() usually is not a problem. However, when
we switch to a new thread we end up scheduler_new_thread_entry() instead
of scheduler_reschedule() what may corrupt data collected by the profiler.

src/system/kernel/scheduler/scheduler.cpp

@@ -495,6 +495,8 @@ reschedule(int32 nextState)
 
 		modeLocker.Unlock();
 
+		SCHEDULER_EXIT_FUNCTION();
+
 		if (nextThread != oldThread)
 			switch_thread(oldThread, nextThread);
 	}

src/system/kernel/scheduler/scheduler_profiler.h

@@ -16,6 +16,9 @@
 #define SCHEDULER_ENTER_FUNCTION()	\
 	Scheduler::Profiling::Function schedulerProfiler(__PRETTY_FUNCTION__)
 
+#define SCHEDULER_EXIT_FUNCTION()	\
+	schedulerProfiler.Exit()
+
 
 namespace Scheduler {
 
@@ -124,6 +127,7 @@ Function::Exit()
 #else	// SCHEDULER_PROFILING
 
 #define SCHEDULER_ENTER_FUNCTION()	(void)0
+#define SCHEDULER_EXIT_FUNCTION()	(void)0
 
 #endif	// !SCHEDULER_PROFILING