ALSA: usb-audio: ignore broken processing/extension unit

ALSA: usb-audio: ignore broken processing/extension unit

[ Upstream commit d8d0db7bb358ef65d60726a61bfcd08eccff0bc0 ]

Some devices have broken extension unit where getting current value
doesn't work. Attempt that once when creating mixer control for it. If
it fails, just ignore it, so that it won't cripple the device entirely
(and/or make the error floods).

Signed-off-by: Tom Yan <tom.ty89@gmail.com>
Link: https://lore.kernel.org/r/5f3abc52.1c69fb81.9cf2.fe91@mx.google.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>