ALSA: compress: Don't allow paritial drain operations on capture streams

Partial drain and next track are intended for gapless playback and
don't really have an obvious interpretation for a capture stream, so
makes sense to not allow those operations on capture streams.

Signed-off-by: Charles Keepax <[e-mail]>
Acked-by: Vinod Koul <[e-mail]>
Signed-off-by: Takashi Iwai <[e-mail]>

sound/core/compress_offload.c

···
 	if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING)
 		return -EPERM;
 
+	/* next track doesn't have any meaning for capture streams */
+	if (stream->direction == SND_COMPRESS_CAPTURE)
+		return -EPERM;
+
 	/* you can signal next track if this is intended to be a gapless stream
 	 * and current track metadata is set
 	 */
···
 	default:
 		break;
 	}
+
+	/* partial drain doesn't have any meaning for capture streams */
+	if (stream->direction == SND_COMPRESS_CAPTURE)
+		return -EPERM;
 
 	/* stream can be drained only when next track has been signalled */
 	if (stream->next_track == false)