ALSA: make snd_ctl_elem_read() and snd_ctl_elem_write() static

snd_ctl_elem_read() and snd_ctl_elem_write() are no longer used by
any other drivers.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
diff --git a/sound/core/control.c b/sound/core/control.c
index 01a1a5a..281b2e2 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -684,7 +684,8 @@
 	return result;
 }
 
-int snd_ctl_elem_read(struct snd_card *card, struct snd_ctl_elem_value *control)
+static int snd_ctl_elem_read(struct snd_card *card,
+			     struct snd_ctl_elem_value *control)
 {
 	struct snd_kcontrol *kctl;
 	struct snd_kcontrol_volatile *vd;
@@ -734,8 +735,8 @@
 	return result;
 }
 
-int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
-		       struct snd_ctl_elem_value *control)
+static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
+			      struct snd_ctl_elem_value *control)
 {
 	struct snd_kcontrol *kctl;
 	struct snd_kcontrol_volatile *vd;