ALSA: usb-audio: convert list_for_each to entry variant

Change occurances of list_for_each into list_for_each_entry where
applicable.

Signed-off-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/midi.c b/sound/usb/midi.c
index 34b9bb7..1cf943d 100644
--- a/sound/usb/midi.c
+++ b/sound/usb/midi.c
@@ -1465,10 +1465,9 @@
 static struct snd_rawmidi_substream *snd_usbmidi_find_substream(struct snd_usb_midi* umidi,
 								int stream, int number)
 {
-	struct list_head* list;
+	struct snd_rawmidi_substream *substream;
 
-	list_for_each(list, &umidi->rmidi->streams[stream].substreams) {
-		struct snd_rawmidi_substream *substream = list_entry(list, struct snd_rawmidi_substream, list);
+	list_for_each_entry(substream, &umidi->rmidi->streams[stream].substreams, list) {
 		if (substream->number == number)
 			return substream;
 	}