[media] em28xx: Remove useless runtime->private_data usage

Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/em28xx/em28xx-audio.c

@@ -306,7 +306,6 @@ static int snd_em28xx_capture_open(struct snd_pcm_substream *substream)
 
 	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 	dev->adev.capture_pcm_substream = substream;
-	runtime->private_data = dev;
 
 	return 0;
 err: