ALSA: usb-audio: avoid freeing umidi object twice

The 'umidi' object will be free'd on the error path by snd_usbmidi_free()
when tearing down the rawmidi interface. So we shouldn't try to free it
in snd_usbmidi_create() after having registered the rawmidi interface.

Found by KASAN.

Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
static int send_bulk_static_data(struct snd_usb_midi_out_endpoint *ep,
				 const void *data, int len)
{
	int err = 0;
	void *buf = kmemdup(data, len, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;
	dump_urb("sending", buf, len);
	if (ep->urbs[0].urb)
		err = usb_bulk_msg(ep->umidi->dev, ep->urbs[0].urb->pipe,
				   buf, len, NULL, 250);
	kfree(buf);
	return err;
}

static int send_bulk_static_data(struct snd_usb_midi_out_endpoint *ep,
				 const void *data, int len)
{
	int err = 0;
	void *buf = kmemdup(data, len, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;
	dump_urb("sending", buf, len);
	if (ep->urbs[0].urb)
		err = usb_bulk_msg(ep->umidi->dev, ep->urbs[0].urb->pipe,
				   buf, len, NULL, 250);
	kfree(buf);
	return err;
}
