ALSA: snd-usb-caiaq: fix stream count check

Commit 897c329bc ("ALSA: usb: caiaq: check for cdev->n_streams > 1")
introduced a safety check to protect against bogus data provided by
devices. However, the n_streams variable is already divided by
CHANNELS_PER_STREAM, so the correct check is 'n_streams > 0'.

Fix this to un-break support for stereo devices.

Signed-off-by: Daniel Mack <daniel@zonque.org>
Cc: stable@kernel.org [v3.18+]
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/caiaq/audio.c

@@ -816,7 +816,7 @@ int snd_usb_caiaq_audio_init(struct snd_usb_caiaqdev *cdev)
 		return -EINVAL;
 	}
 
-	if (cdev->n_streams < 2) {
+	if (cdev->n_streams < 1) {
 		dev_err(dev, "bogus number of streams: %d\n", cdev->n_streams);
 		return -EINVAL;
 	}