ALSA: vx: vx_pcm: constify vx_pcm_playback_ops and vx_pcm_capture_ops.

File size before:
   text	   data	    bss	    dec	    hex	filename
   7126	    240	      0	   7366	   1cc6	sound/drivers/vx/vx_pcm.o

File size After adding 'const':
   text	   data	    bss	    dec	    hex	filename
   7382	      0	      0	   7382	   1cd6	sound/drivers/vx/vx_pcm.o
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/drivers/vx/vx_pcm.c

@@ -873,7 +873,7 @@ static int vx_pcm_prepare(struct snd_pcm_substream *subs)
 /*
  * operators for PCM playback
  */
-static struct snd_pcm_ops vx_pcm_playback_ops = {
+static const struct snd_pcm_ops vx_pcm_playback_ops = {
 	.open =		vx_pcm_playback_open,
 	.close =	vx_pcm_playback_close,
 	.ioctl =	snd_pcm_lib_ioctl,
@@ -1095,7 +1095,7 @@ static snd_pcm_uframes_t vx_pcm_capture_pointer(struct snd_pcm_substream *subs)
 /*
  * operators for PCM capture
  */
-static struct snd_pcm_ops vx_pcm_capture_ops = {
+static const struct snd_pcm_ops vx_pcm_capture_ops = {
 	.open =		vx_pcm_capture_open,
 	.close =	vx_pcm_capture_close,
 	.ioctl =	snd_pcm_lib_ioctl,