locking/mutex: Fix mutex debug call and ww_mutex documentation

The following commit:

  08295b3 ("Implement an algorithm choice for Wound-Wait mutexes")

introduced a reference in the documentation to a function that was
removed in an earlier commit.

It also forgot to remove a call to debug_mutex_add_waiter() which is now
unconditionally called by __mutex_add_waiter().

Fix those bugs.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dri-devel@lists.freedesktop.org
Fixes: 08295b3 ("Implement an algorithm choice for Wound-Wait mutexes")
Link: http://lkml.kernel.org/r/20180903140708.2401-1-thellstrom@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/locking/mutex.c

@@ -389,7 +389,7 @@ static bool __ww_mutex_wound(struct mutex *lock,
 		/*
 		 * wake_up_process() paired with set_current_state()
 		 * inserts sufficient barriers to make sure @owner either sees
-		 * it's wounded in __ww_mutex_lock_check_stamp() or has a
+		 * it's wounded in __ww_mutex_check_kill() or has a
 		 * wakeup pending to re-read the wounded state.
 		 */
 		if (owner != current)
@@ -946,7 +946,6 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 	}
 
 	debug_mutex_lock_common(lock, &waiter);
-	debug_mutex_add_waiter(lock, &waiter, current);
 
 	lock_contended(&lock->dep_map, ip);