ALSA: usb-audio: remove some dead code

ALSA: usb-audio: remove some dead code

BugLink: https://bugs.launchpad.net/bugs/1852338
commit b39e077fcb283dd96dd251a3abeba585402c61fe upstream.

We recently cleaned up the error handling in commit 52c3e317a857 ("ALSA:
usb-audio: Unify the release of usb_mixer_elem_info objects") but
accidentally left this stray return.

Fixes: 52c3e317a857 ("ALSA: usb-audio: Unify the release of usb_mixer_elem_info objects")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>