Correct compiler warnings.

It seems that the audio callback will keep being called after exit
unless rb->pcm_play_stop() is called again.

apps/plugins/varvara/varvara.c

@@ -32,7 +32,7 @@ static Uxn u;
 static Ppu ppu;
 static Apu apu[POLYPHONY];
 static Device *devctrl, *devsystem, *devconsole, *devscreen, *devaudio0;
-unsigned int palette[3];
+unsigned int palette[4];
 static Uint8 framebuffer[LCD_HEIGHT * LCD_WIDTH * 4];
 static fb_data *lcd_fb = NULL;
 char audio_buf[AUDIO_BUF_SIZE];
@@ -49,6 +49,7 @@ memzero8(void *src, uint64_t n)
     }
 }
 
+#if 0
 /* taken from uxncli */
 static void
 inspect(Stack *s, char *name)
@@ -64,6 +65,7 @@ inspect(Stack *s, char *name)
 		DEBUGF("\n");
 	}
 }
+#endif
 
 static void
 set_palette(Uint8 *addr)
@@ -104,6 +106,7 @@ static Uint8 system_dei(Device *d, Uint8 port) {
 	switch(port) {
 	case 0x2: return d->u->wst.ptr; break;
 	case 0x3: return d->u->rst.ptr; break;
+	default: return d->dat[port];
 	}
 }
 
@@ -114,7 +117,7 @@ console_deo(Device *d, Uint8 port)
 	if(port == 0x1)
 		d->vector = peek16(d->dat, 0x0);
 	if(port > 0x7)
-		DEBUGF("%c",(char *)&d->dat[port]);
+		DEBUGF("%c", d->dat[port]);
 }
 
 /* taken from uxnemu */
@@ -128,7 +131,6 @@ screen_dei(Device *d, Uint8 port)
 		case 0x5: return ppu.height; break;
 		default: return d->dat[port];
 	}
-	return 1;
 }
 
 static void
@@ -189,9 +191,9 @@ nil_deo(Device *d, Uint8 port)
 static Uint8
 nil_dei(Device *d, Uint8 port)
 {
-	(void)d;
-	(void)port;
+	return d->dat[port];
 }
+
 static Uint8
 datetime_dei(Device *d, Uint8 port)
 {
@@ -217,6 +219,7 @@ void
 apu_finished_handler(Apu *c)
 {
 	DEBUGF("APU done\n");
+	(void) c;
 }
 
 void audio_callback(const void** start, size_t *size) {
@@ -224,7 +227,7 @@ void audio_callback(const void** start, size_t *size) {
 	*start = audio_buf;
 	*size = AUDIO_BUF_SIZE;
 	memzero8(audio_buf, AUDIO_BUF_SIZE);
-	apu_render(&apu[0], audio_buf, audio_buf + AUDIO_BUF_SIZE);
+	apu_render(&apu[0], (Sint16 *)audio_buf, (Sint16 *)(audio_buf + AUDIO_BUF_SIZE));
 }
 
 static Uint8
@@ -291,9 +294,10 @@ uxn_halt(Uxn *u, Uint8 error, char *name, int id)
 {
 	rb->splash(HZ, "Halted\n");
 	return 0;
+	(void) u; (void) error; (void) name; (void) id;
 }
 
-static void run() {
+static void run(void) {
 	while(!devsystem->dat[0xf]) {
 		starttick = *rb->current_tick;
 		uxn_eval(&u, devscreen->vector);
@@ -411,6 +415,8 @@ enum plugin_status plugin_start(const void* parameter)
 	/* empty    */ uxn_port(&u, 0xf, nil_dei, nil_deo);
     uxn_eval(&u, 0x0100);
 	run();
+	rb->pcm_play_stop();
+	rb->pcm_set_frequency(HW_SAMPR_DEFAULT);
 	file_cleanup();
 	return PLUGIN_OK;