locking/rwsem: Remove a few useless comments

Our rwsem code (xadd, at least) is rather well documented, but
there are a few really annoying comments in there that serve
no purpose and we shouldn't bother with them.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman.Long@hp.com
Cc: dave@stgolabs.net
Cc: jason.low2@hpe.com
Cc: wanpeng.li@hotmail.com
Link: http://lkml.kernel.org/r/1470384285-32163-3-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/locking/rwsem-xadd.c

@@ -234,7 +234,6 @@ struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem)
 	struct task_struct *tsk = current;
 	WAKE_Q(wake_q);
 
-	/* set up my own style of waitqueue */
 	waiter.task = tsk;
 	waiter.type = RWSEM_WAITING_FOR_READ;
 
@@ -613,7 +612,6 @@ struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem)
 	raw_spin_lock_irqsave(&sem->wait_lock, flags);
 locked:
 
-	/* do nothing if list empty */
 	if (!list_empty(&sem->wait_list))
 		__rwsem_mark_wake(sem, RWSEM_WAKE_ANY, &wake_q);
 
@@ -637,7 +635,6 @@ struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem)
 
 	raw_spin_lock_irqsave(&sem->wait_lock, flags);
 
-	/* do nothing if list empty */
 	if (!list_empty(&sem->wait_list))
 		__rwsem_mark_wake(sem, RWSEM_WAKE_READ_OWNED, &wake_q);