locking/mutex: Checking the stamp is WW only

Mark it so by renaming __mutex_lock_check_stamp().

Signed-off-by: Davidlohr Bueso <[e-mail]>
Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
Cc: "Paul E. McKenney" <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

kernel/locking/mutex.c

···
 EXPORT_SYMBOL(ww_mutex_unlock);
 
 static inline int __sched
-__mutex_lock_check_stamp(struct mutex *lock, struct ww_acquire_ctx *ctx)
+__ww_mutex_lock_check_stamp(struct mutex *lock, struct ww_acquire_ctx *ctx)
 {
 	struct ww_mutex *ww = container_of(lock, struct ww_mutex, base);
 	struct ww_acquire_ctx *hold_ctx = ACCESS_ONCE(ww->ctx);
···
 		}
 
 		if (use_ww_ctx && ww_ctx->acquired > 0) {
-			ret = __mutex_lock_check_stamp(lock, ww_ctx);
+			ret = __ww_mutex_lock_check_stamp(lock, ww_ctx);
 			if (ret)
 				goto err;
 		}