Use new tty helpers for close, which allows much code removal.

The only real change is locking. card_lock for protecting was
used inappropriately (just to have a critical section, no matter
which lock is used), so the change to port->lock is fine.

Remove also useless debug printks while being there.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>