Revert "SX(9): Implement with reader/writer lock"

This was accidentally committed.

This reverts commit cc7a8d87e7.

freebsd/sys/sys/_sx.h

@@ -31,7 +31,7 @@
 #ifndef	_SYS__SX_H_
 #define	_SYS__SX_H_
 #ifdef __rtems__
-#include <machine/rtems-bsd-rwlock.h>
+#include <machine/rtems-bsd-mutex.h>
 #endif /* __rtems__ */
 
 /*
@@ -42,7 +42,7 @@ struct sx {
 #ifndef __rtems__
 	volatile uintptr_t	sx_lock;
 #else /* __rtems__ */
-	rtems_bsd_rwlock	rwlock;
+	rtems_bsd_mutex mutex;
 #endif /* __rtems__ */
 };
 

freebsd/sys/sys/sx.h

@@ -44,6 +44,9 @@
 
 #ifdef __rtems__
 #define SX_NOINLINE 1
+#define _sx_slock _bsd__sx_xlock
+#define sx_try_slock_ _bsd_sx_try_xlock_
+#define _sx_sunlock _bsd__sx_xunlock
 #endif /* __rtems__ */
 /*
  * In general, the sx locks and rwlocks use very similar algorithms.