ALSA: OSS mixer emulation - fix locking

Fix mutex release and cleanup some locking code.

Cc: <stable@kernel.org>
Signed-off-by: NJaroslav Kysela <perex@perex.cz>

sound/core/oss/mixer_oss.c

@@ -618,8 +618,10 @@ static void snd_mixer_oss_put_volume1_vol(struct snd_mixer_oss_file *fmixer,
 	if (numid == ID_UNKNOWN)
 		return;
 	down_read(&card->controls_rwsem);
-	if ((kctl = snd_ctl_find_numid(card, numid)) == NULL)
+	if ((kctl = snd_ctl_find_numid(card, numid)) == NULL) {
+		up_read(&card->controls_rwsem);
 		return;
+	}
 	uinfo = kzalloc(sizeof(*uinfo), GFP_KERNEL);
 	uctl = kzalloc(sizeof(*uctl), GFP_KERNEL);
 	if (uinfo == NULL || uctl == NULL)
@@ -658,7 +660,7 @@ static void snd_mixer_oss_put_volume1_sw(struct snd_mixer_oss_file *fmixer,
 		return;
 	down_read(&card->controls_rwsem);
 	if ((kctl = snd_ctl_find_numid(card, numid)) == NULL) {
-		up_read(&fmixer->card->controls_rwsem);
+		up_read(&card->controls_rwsem);
 		return;
 	}
 	uinfo = kzalloc(sizeof(*uinfo), GFP_KERNEL);
@@ -797,7 +799,7 @@ static int snd_mixer_oss_get_recsrc2(struct snd_mixer_oss_file *fmixer, unsigned
 	uctl = kzalloc(sizeof(*uctl), GFP_KERNEL);
 	if (uinfo == NULL || uctl == NULL) {
 		err = -ENOMEM;
-		goto __unlock;
+		goto __free_only;
 	}
 	down_read(&card->controls_rwsem);
 	kctl = snd_mixer_oss_test_id(mixer, "Capture Source", 0);
@@ -826,6 +828,7 @@ static int snd_mixer_oss_get_recsrc2(struct snd_mixer_oss_file *fmixer, unsigned
 	err = 0;
       __unlock:
      	up_read(&card->controls_rwsem);
+      __free_only:
       	kfree(uctl);
       	kfree(uinfo);
       	return err;
@@ -847,7 +850,7 @@ static int snd_mixer_oss_put_recsrc2(struct snd_mixer_oss_file *fmixer, unsigned
 	uctl = kzalloc(sizeof(*uctl), GFP_KERNEL);
 	if (uinfo == NULL || uctl == NULL) {
 		err = -ENOMEM;
-		goto __unlock;
+		goto __free_only;
 	}
 	down_read(&card->controls_rwsem);
 	kctl = snd_mixer_oss_test_id(mixer, "Capture Source", 0);
@@ -880,6 +883,7 @@ static int snd_mixer_oss_put_recsrc2(struct snd_mixer_oss_file *fmixer, unsigned
 	err = 0;
       __unlock:
 	up_read(&card->controls_rwsem);
+      __free_only:
 	kfree(uctl);
 	kfree(uinfo);
 	return err;