ALSA: usb-audio: US16x08: fix value count for level meters

The level meter control returns 34 integers of info. This fixes:

snd-usb-audio 3-1:1.0: control 2:0:0:Level Meter:0: access overflow

Fixes: d2bb390a ("ALSA: usb-audio: Tascam US-16x08 DSP mixer quirk")
Cc: stable@vger.kernel.org
Signed-off-by: Hector Martin <marcan@marcan.st>
Link: https://lore.kernel.org/r/20201127132635.18947-1-marcan@marcan.st


Signed-off-by: Takashi Iwai <tiwai@suse.de>