[ALSA] ALSA's struct _snd_pcm_substream: Obsolete open_flag

PCM Midlevel,ALSA<-OSS emulation,USB USX2Y
This patch removes open_flag from struct _snd_pcm_substream.
All of its uses are substituted by querying struct _snd_pcm_substream's
member ffile instead.

Signed-off-by: Karsten Wiese <annabellesgarden@yahoo.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/usx2y/usx2yhwdeppcm.c b/sound/usb/usx2y/usx2yhwdeppcm.c
index ef280612..d0199c4 100644
--- a/sound/usb/usx2y/usx2yhwdeppcm.c
+++ b/sound/usb/usx2y/usx2yhwdeppcm.c
@@ -624,7 +624,7 @@
 		for (s = 0; s < 2; ++s) {
 			snd_pcm_substream_t *substream;
 			substream = pcm->streams[s].substream;
-			if (substream && substream->open_flag)
+			if (substream && substream->ffile != NULL)
 				err = -EBUSY;
 		}
 	}