sched/wait: Rename wait_queue_t => wait_queue_entry_t

Rename:

	wait_queue_t		=>	wait_queue_entry_t

'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue",
but in reality it's a queue *entry*. The 'real' queue is the wait queue head,
which had to carry the name.

Start sorting this out by renaming it to 'wait_queue_entry_t'.

This also allows the real structure name 'struct __wait_queue' to
lose its double underscore and become 'struct wait_queue_entry',
which is the more canonical nomenclature for such data types.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/fs/dax.c b/fs/dax.c
index 2a6889b..323ea48 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -84,7 +84,7 @@ struct exceptional_entry_key {
 };
 
 struct wait_exceptional_entry_queue {
-	wait_queue_t wait;
+	wait_queue_entry_t wait;
 	struct exceptional_entry_key key;
 };
 
@@ -108,7 +108,7 @@ static wait_queue_head_t *dax_entry_waitqueue(struct address_space *mapping,
 	return wait_table + hash;
 }
 
-static int wake_exceptional_entry_func(wait_queue_t *wait, unsigned int mode,
+static int wake_exceptional_entry_func(wait_queue_entry_t *wait, unsigned int mode,
 				       int sync, void *keyp)
 {
 	struct exceptional_entry_key *key = keyp;