kernel: clean memory when exit

kernel/throne_tracker.h

@@ -1,9 +1,9 @@
 #ifndef __KSU_H_UID_OBSERVER
 #define __KSU_H_UID_OBSERVER
 
-int ksu_throne_tracker_init();
+void ksu_throne_tracker_init();
 
-int ksu_throne_tracker_exit();
+void ksu_throne_tracker_exit();
 
 void track_throne();