oss/alsa: Do not invoke UB described in 7.15.1.1 (this time for ADC)

Signed-off-by: Nmalc <av1474@comtv.ru>

audio/alsaaudio.c

@@ -1079,16 +1079,18 @@ static int alsa_read (SWVoiceIn *sw, void *buf, int size)
 
 static int alsa_ctl_in (HWVoiceIn *hw, int cmd, ...)
 {
+    ALSAVoiceIn *alsa = (ALSAVoiceIn *) hw;
+
+    switch (cmd) {
+    case VOICE_ENABLE:
+        {
             va_list ap;
             int poll_mode;
-    ALSAVoiceIn *alsa = (ALSAVoiceIn *) hw;
 
             va_start (ap, cmd);
             poll_mode = va_arg (ap, int);
             va_end (ap);
 
-    switch (cmd) {
-    case VOICE_ENABLE:
             ldebug ("enabling voice\n");
             if (poll_mode && alsa_poll_in (hw)) {
                 poll_mode = 0;
@@ -1096,6 +1098,7 @@ static int alsa_ctl_in (HWVoiceIn *hw, int cmd, ...)
             hw->poll_mode = poll_mode;
 
             return alsa_voice_ctl (alsa->handle, "capture", 0);
+        }
 
     case VOICE_DISABLE:
         ldebug ("disabling voice\n");

audio/ossaudio.c

@@ -781,20 +781,23 @@ static int oss_read (SWVoiceIn *sw, void *buf, int size)
 
 static int oss_ctl_in (HWVoiceIn *hw, int cmd, ...)
 {
+    OSSVoiceIn *oss = (OSSVoiceIn *) hw;
+
+    switch (cmd) {
+    case VOICE_ENABLE:
+        {
             va_list ap;
             int poll_mode;
-    OSSVoiceIn *oss = (OSSVoiceIn *) hw;
 
             va_start (ap, cmd);
             poll_mode = va_arg (ap, int);
             va_end (ap);
 
-    switch (cmd) {
-    case VOICE_ENABLE:
             if (poll_mode && oss_poll_in (hw)) {
                 poll_mode = 0;
             }
             hw->poll_mode = poll_mode;
+        }
         break;
 
     case VOICE_DISABLE: