tty: Revert the tty locking series, it needs more work

This reverts the tty layer change to use per-tty locking, because it's
not correct yet, and fixing it will require some more deep surgery.

The main revert is d29f3ef39b ("tty_lock: Localise the lock"), but
there are several smaller commits that built upon it, they also get
reverted here. The list of reverted commits is:

  fde86d3108 - tty: add lockdep annotations
  8f6576ad47 - tty: fix ldisc lock inversion trace
  d3ca8b64b9 - pty: Fix lock inversion
  b1d679afd7 - tty: drop the pty lock during hangup
  abcefe5fc3 - tty/amiserial: Add missing argument for tty_unlock()
  fd11b42e35 - cris: fix missing tty arg in wait_event_interruptible_tty call
  d29f3ef39b - tty_lock: Localise the lock

The revert had a trivial conflict in the 68360serial.c staging driver
that got removed in the meantime.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/tty/synclink_gt.c

@@ -3336,9 +3336,9 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
 		}
 
 		DBGINFO(("%s block_til_ready wait\n", tty->driver->name));
-		tty_unlock(tty);
+		tty_unlock();
 		schedule();
-		tty_lock(tty);
+		tty_lock();
 	}
 
 	set_current_state(TASK_RUNNING);