ALSA: usb-audio: Unify audioformat release code

There are many open code for releasing audioformat object.
Provide a unified helper and call it from the all places.

Only a cleanup, no functional changes.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/stream.c

@@ -28,6 +28,14 @@
 #include "power.h"
 #include "media.h"
 
+static void audioformat_free(struct audioformat *fp)
+{
+	list_del(&fp->list); /* unlink for avoiding double-free */
+	kfree(fp->rate_table);
+	kfree(fp->chmap);
+	kfree(fp);
+}
+
 /*
  * free a substream
  */
@@ -37,11 +45,8 @@ static void free_substream(struct snd_usb_substream *subs)
 
 	if (!subs->num_formats)
 		return; /* not initialized */
-	list_for_each_entry_safe(fp, n, &subs->fmt_list, list) {
-		kfree(fp->rate_table);
-		kfree(fp->chmap);
-		kfree(fp);
-	}
+	list_for_each_entry_safe(fp, n, &subs->fmt_list, list)
+		audioformat_free(fp);
 	kfree(subs->rate_list.list);
 	kfree(subs->str_pd);
 	snd_media_stream_delete(subs);
@@ -832,8 +837,7 @@ snd_usb_get_audioformat_uac12(struct snd_usb_audio *chip,
 	/* ok, let's parse further... */
 	if (snd_usb_parse_audio_format(chip, fp, format,
 					fmt, stream) < 0) {
-		kfree(fp->rate_table);
-		kfree(fp);
+		audioformat_free(fp);
 		return NULL;
 	}
 
@@ -1043,9 +1047,7 @@ snd_usb_get_audioformat_uac3(struct snd_usb_audio *chip,
 
 		pd = kzalloc(sizeof(*pd), GFP_KERNEL);
 		if (!pd) {
-			kfree(fp->chmap);
-			kfree(fp->rate_table);
-			kfree(fp);
+			audioformat_free(fp);
 			return NULL;
 		}
 		pd->pd_id = (stream == SNDRV_PCM_STREAM_PLAYBACK) ?
@@ -1064,9 +1066,7 @@ snd_usb_get_audioformat_uac3(struct snd_usb_audio *chip,
 		/* ok, let's parse further... */
 		if (snd_usb_parse_audio_format_v3(chip, fp, as, stream) < 0) {
 			kfree(pd);
-			kfree(fp->chmap);
-			kfree(fp->rate_table);
-			kfree(fp);
+			audioformat_free(fp);
 			return NULL;
 		}
 	}
@@ -1185,11 +1185,8 @@ int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no)
 			err = snd_usb_add_audio_stream(chip, stream, fp);
 
 		if (err < 0) {
-			list_del(&fp->list); /* unlink for avoiding double-free */
+			audioformat_free(fp);
 			kfree(pd);
-			kfree(fp->rate_table);
-			kfree(fp->chmap);
-			kfree(fp);
 			return err;
 		}
 		/* try to set the interface... */