sound: Use static const char * const where possible

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index e2e7389..eb40942 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -142,7 +142,7 @@
 
 #ifdef RULES_DEBUG
 #define HW_PARAM(v) [SNDRV_PCM_HW_PARAM_##v] = #v
-char *snd_pcm_hw_param_names[] = {
+static const char * const snd_pcm_hw_param_names[] = {
 	HW_PARAM(ACCESS),
 	HW_PARAM(FORMAT),
 	HW_PARAM(SUBFORMAT),