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/mm/shmem.c b/mm/shmem.c
index e67d6ba..a6c7dec 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1902,7 +1902,7 @@ alloc_nohuge:		page = shmem_alloc_and_acct_page(gfp, info, sbinfo,
  * entry unconditionally - even if something else had already woken the
  * target.
  */
-static int synchronous_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key)
+static int synchronous_wake_function(wait_queue_entry_t *wait, unsigned mode, int sync, void *key)
 {
 	int ret = default_wake_function(wait, mode, sync, key);
 	list_del_init(&wait->task_list);