UPSTREAM: 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>

Bug: 27300729

(cherry picked from commit 07d86ca93db7e5cdf4743564d98292042ec21af7)
Signed-off-by: Kees Cook <keescook@google.com>
Change-Id: I1b68e347c30a72e3393ae359aeec15ec453d4e7b
diff --git a/sound/usb/midi.c b/sound/usb/midi.c
index c7aa71e..e3d49fa 100644
--- a/sound/usb/midi.c
+++ b/sound/usb/midi.c
@@ -2319,7 +2319,6 @@
 	else
 		err = snd_usbmidi_create_endpoints(umidi, endpoints);
 	if (err < 0) {
-		snd_usbmidi_free(umidi);
 		return err;
 	}