tty/amiserial: Add missing argument for tty_unlock()

commit d29f3ef3 ("tty_lock: Localise the lock")
missed that d3a7b83f ("drivers/tty/amiserial.c:
add missing tty_unlock") just added a new caller of tty_unlock():

drivers/tty/amiserial.c: In function ‘set_serial_info’:
drivers/tty/amiserial.c:1077: error: too few arguments to function ‘tty_unlock’
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/amiserial.c

@@ -1074,7 +1074,7 @@ static int set_serial_info(struct tty_struct *tty, struct serial_state *state,
 		    (new_serial.xmit_fifo_size != state->xmit_fifo_size) ||
 		    ((new_serial.flags & ~ASYNC_USR_MASK) !=
 		     (port->flags & ~ASYNC_USR_MASK))) {
-			tty_unlock();
+			tty_unlock(tty);
 			return -EPERM;
 		}
 		port->flags = ((port->flags & ~ASYNC_USR_MASK) |