- Make the eventhandler_mutex mutex a private variable in

subr_eventhandler.c
- Move the extra #include's in sys/eventhandler.h to be protected by
  the #ifndef SYS_EVENTHANDLER/#endif

sys/kern/subr_eventhandler.c

@@ -37,6 +37,7 @@ MALLOC_DEFINE(M_EVENTHANDLER, "eventhandler", "Event handler records");
 /* List of 'slow' lists */
 static TAILQ_HEAD(, eventhandler_list)	eventhandler_lists;
 static int				eventhandler_lists_initted = 0;
+static struct mtx			eventhandler_mutex;
 
 struct eventhandler_entry_generic 
 {

sys/sys/eventhandler.h

@@ -26,12 +26,12 @@
  * $FreeBSD$
  */
 
-#include <sys/queue.h>
-#include <sys/mutex.h>
-
 #ifndef SYS_EVENTHANDLER_H
 #define SYS_EVENTHANDLER_H
 
+#include <sys/queue.h>
+#include <sys/mutex.h>
+
 struct eventhandler_entry 
 {
     TAILQ_ENTRY(eventhandler_entry)	ee_link;
@@ -50,7 +50,6 @@ struct eventhandler_list
 };
 
 typedef struct eventhandler_entry	*eventhandler_tag;
-struct mtx				eventhandler_mutex;
 
 /* 
  * Fast handler lists require the eventhandler list be present