xhci: dbgtty: fix device unregister: fixup

This fixup replaces tty_vhangup() call with call to
tty_port_tty_vhangup(). Both calls hangup tty device
synchronously however tty_port_tty_vhangup() increases
reference count during the hangup operation using
scoped_guard(tty_port_tty).

Cc: stable <stable@kernel.org>
Fixes: 1f73b8b ("xhci: dbgtty: fix device unregister")
Signed-off-by: Łukasz Bartosik <ukaszb@chromium.org>
Link: https://patch.msgid.link/20251127111644.3161386-1-ukaszb@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Łukasz Bartosik

drivers/usb/host/xhci-dbgtty.c

@@ -554,7 +554,7 @@ static void xhci_dbc_tty_unregister_device(struct xhci_dbc *dbc)
 	 * Hang up the TTY. This wakes up any blocked
 	 * writers and causes subsequent writes to fail.
 	 */
-	tty_vhangup(port->port.tty);
+	tty_port_tty_vhangup(&port->port);
 
 	tty_unregister_device(dbc_tty_driver, port->minor);
 	xhci_dbc_tty_exit_port(port);