[ALSA] Clean up with common snd_ctl_boolean_*_info callbacks

Clean up codes using the new common snd_ctl_boolean_*_info() callbacks.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
diff --git a/sound/isa/gus/gus_mixer.c b/sound/isa/gus/gus_mixer.c
index acc25a2..7f6aefd4 100644
--- a/sound/isa/gus/gus_mixer.c
+++ b/sound/isa/gus/gus_mixer.c
@@ -36,14 +36,7 @@
   .get = snd_gf1_get_single, .put = snd_gf1_put_single, \
   .private_value = shift | (invert << 8) }
 
-static int snd_gf1_info_single(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo)
-{
-	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
-	uinfo->count = 1;
-	uinfo->value.integer.min = 0;
-	uinfo->value.integer.max = 1;
-	return 0;
-}
+#define snd_gf1_info_single	snd_ctl_boolean_mono_info
 
 static int snd_gf1_get_single(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
 {