[ALSA] sound/core/: fix 3 off-by-one errors

This patch fixes three off-by-one errors found by the Coverity checker.
Signed-off-by: Adrian Bunk <bunk@stusta.de>

sound/core/sound.c

@@ -120,7 +120,7 @@ void *snd_lookup_minor_data(unsigned int minor, int type)
 	struct snd_minor *mreg;
 	void *private_data;
 
-	if (minor > ARRAY_SIZE(snd_minors))
+	if (minor >= ARRAY_SIZE(snd_minors))
 		return NULL;
 	down(&sound_mutex);
 	mreg = snd_minors[minor];
@@ -139,7 +139,7 @@ static int snd_open(struct inode *inode, struct file *file)
 	struct file_operations *old_fops;
 	int err = 0;
 
-	if (minor > ARRAY_SIZE(snd_minors))
+	if (minor >= ARRAY_SIZE(snd_minors))
 		return -ENODEV;
 	mptr = snd_minors[minor];
 	if (mptr == NULL) {

sound/core/sound_oss.c

@@ -45,7 +45,7 @@ void *snd_lookup_oss_minor_data(unsigned int minor, int type)
 	struct snd_minor *mreg;
 	void *private_data;
 
-	if (minor > ARRAY_SIZE(snd_oss_minors))
+	if (minor >= ARRAY_SIZE(snd_oss_minors))
 		return NULL;
 	down(&sound_oss_mutex);
 	mreg = snd_oss_minors[minor];