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>

fs/nfs/nfs4proc.c

@@ -6372,7 +6372,7 @@ struct nfs4_lock_waiter {
 };
 
 static int
-nfs4_wake_lock_waiter(wait_queue_t *wait, unsigned int mode, int flags, void *key)
+nfs4_wake_lock_waiter(wait_queue_entry_t *wait, unsigned int mode, int flags, void *key)
 {
 	int ret;
 	struct cb_notify_lock_args *cbnl = key;
@@ -6415,7 +6415,7 @@ nfs4_retry_setlk(struct nfs4_state *state, int cmd, struct file_lock *request)
 					   .inode = state->inode,
 					   .owner = &owner,
 					   .notified = false };
-	wait_queue_t wait;
+	wait_queue_entry_t wait;
 
 	/* Don't bother with waitqueue if we don't expect a callback */
 	if (!test_bit(NFS_STATE_MAY_NOTIFY_LOCK, &state->flags))