USB: serial, use tty_standard_install

But before that we need to reorder the calls so that we don't need to
lower the reference counts if usb_autopm_get_interface fails.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/serial/usb-serial.c

@@ -214,15 +214,14 @@ static int serial_install(struct tty_driver *driver, struct tty_struct *tty)
 	if (!try_module_get(serial->type->driver.owner))
 		goto error_module_get;
 
-	/* perform the standard setup */
-	retval = tty_init_termios(tty);
-	if (retval)
-		goto error_init_termios;
-
 	retval = usb_autopm_get_interface(serial->interface);
 	if (retval)
 		goto error_get_interface;
 
+	retval = tty_standard_install(driver, tty);
+	if (retval)
+		goto error_init_termios;
+
 	mutex_unlock(&serial->disc_mutex);
 
 	/* allow the driver to update the settings */
@@ -231,14 +230,11 @@ static int serial_install(struct tty_driver *driver, struct tty_struct *tty)
 
 	tty->driver_data = port;
 
-	/* Final install (we use the default method) */
-	tty_driver_kref_get(driver);
-	tty->count++;
-	driver->ttys[idx] = tty;
 	return retval;
 
- error_get_interface:
  error_init_termios:
+	usb_autopm_put_interface(serial->interface);
+ error_get_interface:
 	module_put(serial->type->driver.owner);
  error_module_get:
  error_no_port: