ALSA: usb-audio: Don't abort even if the clock rate differs

The commit 93db51d ("ALSA: usb-audio: Check valid altsetting at
parsing rates for UAC2/3") changed the behavior of the function
set_sample_rate_v2v3() slightly to treat the inconsistent sample rate
as an error.  It was done by assumption that the sample rate
validation should have been done at the parser phase as implemented in
that patch.  But the validation is later selectively enabled only for
certain devices as it causes a regression (the commit fe773b8
"ALSA: usb-audio: workaround for iface reset issue"), and now the
inconsistency surfaced as a fatal error while it worked in the past as
is, as reported for FiiO M3K DAC.

For recovering from the regression, change set_sample_rate_v2v3()
again to ignore the sample rate difference as non-error.

BugLink: https://bugzilla.opensuse.org/show_bug.cgi?id=1182633
Fixes: 93db51d ("ALSA: usb-audio: Check valid altsetting at parsing rates for UAC2/3")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210227082002.21185-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/clock.c

@@ -652,10 +652,10 @@ static int set_sample_rate_v2v3(struct snd_usb_audio *chip,
 		cur_rate = prev_rate;
 
 	if (cur_rate != rate) {
-		usb_audio_warn(chip,
-			       "%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n",
-			       fmt->iface, fmt->altsetting, rate, cur_rate);
-		return -ENXIO;
+		usb_audio_dbg(chip,
+			      "%d:%d: freq mismatch: req %d, clock runs @%d\n",
+			      fmt->iface, fmt->altsetting, rate, cur_rate);
+		/* continue processing */
 	}
 
 validation: