ALSA: usb-audio: silence a superfluous warning

It is not advisable to print a warning when a device does not support
setting the sample rate because this is perfectly valid for devices with
a single rate or where rates are implicitly changed by selecting another
alternate setting.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/clock.c b/sound/usb/clock.c
index 66bd157..b853f8d 100644
--- a/sound/usb/clock.c
+++ b/sound/usb/clock.c
@@ -204,11 +204,8 @@
 	ep = get_endpoint(alts, 0)->bEndpointAddress;
 
 	/* if endpoint doesn't have sampling rate control, bail out */
-	if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE)) {
-		snd_printk(KERN_WARNING "%d:%d:%d: endpoint lacks sample rate attribute bit, cannot set.\n",
-				   dev->devnum, iface, fmt->altsetting);
+	if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
 		return 0;
-	}
 
 	data[0] = rate;
 	data[1] = rate >> 8;