ALSA: bt87x: constify snd_pcm_ops structures

Check for snd_pcm_ops structures that are only stored in the ops field of a
snd_soc_platform_driver structure or passed as the third argument to
snd_pcm_set_ops.  The corresponding field or parameter is declared const,
so snd_pcm_ops structures that have this property can be declared as const
also.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r disable optional_qualifier@
identifier i;
position p;
@@
static struct snd_pcm_ops i@p = { ... };

@ok1@
identifier r.i;
struct snd_soc_platform_driver e;
position p;
@@
e.ops = &i@p;

@ok2@
identifier r.i;
expression e1, e2;
position p;
@@
snd_pcm_set_ops(e1, e2, &i@p)

@bad@
position p != {r.p,ok1.p,ok2.p};
identifier r.i;
struct snd_pcm_ops e;
@@
e@i@p

@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
 struct snd_pcm_ops i = { ... };
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/bt87x.c

@@ -550,7 +550,7 @@ static snd_pcm_uframes_t snd_bt87x_pointer(struct snd_pcm_substream *substream)
 	return (snd_pcm_uframes_t)bytes_to_frames(runtime, chip->current_line * chip->line_bytes);
 }
 
-static struct snd_pcm_ops snd_bt87x_pcm_ops = {
+static const struct snd_pcm_ops snd_bt87x_pcm_ops = {
 	.open = snd_bt87x_pcm_open,
 	.close = snd_bt87x_close,
 	.ioctl = snd_pcm_lib_ioctl,