ALSA: usb-audio: Minor code cleanup in create_fixed_stream_quirk()

Just a minor code cleanup: unify the error paths.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 529c35c..a889d43 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -167,23 +167,18 @@
 	stream = (fp->endpoint & USB_DIR_IN)
 		? SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
 	err = snd_usb_add_audio_stream(chip, stream, fp);
-	if (err < 0) {
-		kfree(fp);
-		kfree(rate_table);
-		return err;
-	}
+	if (err < 0)
+		goto error;
 	if (fp->iface != get_iface_desc(&iface->altsetting[0])->bInterfaceNumber ||
 	    fp->altset_idx >= iface->num_altsetting) {
-		kfree(fp);
-		kfree(rate_table);
-		return -EINVAL;
+		err = -EINVAL;
+		goto error;
 	}
 	alts = &iface->altsetting[fp->altset_idx];
 	altsd = get_iface_desc(alts);
 	if (altsd->bNumEndpoints < 1) {
-		kfree(fp);
-		kfree(rate_table);
-		return -EINVAL;
+		err = -EINVAL;
+		goto error;
 	}
 
 	fp->protocol = altsd->bInterfaceProtocol;
@@ -196,6 +191,11 @@
 	snd_usb_init_pitch(chip, fp->iface, alts, fp);
 	snd_usb_init_sample_rate(chip, fp->iface, alts, fp, fp->rate_max);
 	return 0;
+
+ error:
+	kfree(fp);
+	kfree(rate_table);
+	return err;
 }
 
 static int create_auto_pcm_quirk(struct snd_usb_audio *chip,