ALSA: line6: Support assymetrical in/out configurations

Splits max_packet_size to max_packet_size_in/out (e.g. for
different channel counts).

Signed-off-by: Andrej Krutak <dev@andree.sk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/line6/playback.c

@@ -195,7 +195,7 @@ static int submit_audio_out_urb(struct snd_line6_pcm *line6pcm)
 	urb_frames = urb_size / bytes_per_frame;
 	urb_out->transfer_buffer =
 	    line6pcm->out.buffer +
-	    index * LINE6_ISO_PACKETS * line6pcm->max_packet_size;
+	    index * LINE6_ISO_PACKETS * line6pcm->max_packet_size_out;
 	urb_out->transfer_buffer_length = urb_size;
 	urb_out->context = line6pcm;