mfd: dln2: Fix memory leak in dln2_probe()

When dln2_setup_rx_urbs() in dln2_probe() fails, error out_free forgets
to call usb_put_dev() to decrease the refcount of dln2->usb_dev.

Fix this by adding usb_put_dev() in the error handling code of
dln2_probe().
Signed-off-by: Qiang Ning <qning0106@126.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230330024353.4503-1-qning0106@126.com

drivers/mfd/dln2.c

@@ -827,6 +827,7 @@ static int dln2_probe(struct usb_interface *interface,
 	dln2_stop_rx_urbs(dln2);
 
 out_free:
+	usb_put_dev(dln2->usb_dev);
 	dln2_free(dln2);
 
 	return ret;