USB: usb-serial: replace shutdown with disconnect, release

This patch (as1254) splits up the shutdown method of usb_serial_driver
into a disconnect and a release method.

The problem is that the usb-serial core was calling shutdown during
disconnect handling, but drivers didn't expect it to be called until
after all the open file references had been closed.  The result was an
oops when the close method tried to use memory that had been
deallocated by shutdown.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/pl2303.c

@@ -878,7 +878,7 @@ static void pl2303_break_ctl(struct tty_struct *tty, int break_state)
 		dbg("%s - error sending break = %d", __func__, result);
 }
 
-static void pl2303_shutdown(struct usb_serial *serial)
+static void pl2303_release(struct usb_serial *serial)
 {
 	int i;
 	struct pl2303_private *priv;
@@ -890,7 +890,6 @@ static void pl2303_shutdown(struct usb_serial *serial)
 		if (priv) {
 			pl2303_buf_free(priv->buf);
 			kfree(priv);
-			usb_set_serial_port_data(serial->port[i], NULL);
 		}
 	}
 }
@@ -1123,7 +1122,7 @@ static struct usb_serial_driver pl2303_device = {
 	.write_room =		pl2303_write_room,
 	.chars_in_buffer =	pl2303_chars_in_buffer,
 	.attach =		pl2303_startup,
-	.shutdown =		pl2303_shutdown,
+	.release =		pl2303_release,
 };
 
 static int __init pl2303_init(void)