Fix compiler warnings

Audio.cpp

 	const int16_t *src, *end;
 	int16_t *dest;
 	audio_block_t *block;
-	uint32_t saddr, offset;
+	uint32_t saddr;
 
 	saddr = (uint32_t)DMA_TCD4_SADDR;
         DMA_CINT = 4;
 	}
 	block = AudioOutputAnalog::block_left_1st;
 	if (block) {
-		src = &block->data[offset];
+		src = block->data;
 		do {
 			// TODO: this should probably dither
 			*dest++ = ((*src++) + 32767) >> 4;

Audio.h

 {
 public:
   AudioSynthWaveform(void) : 
-  AudioStream(0,NULL), tone_amp(0), ramp_up(0), ramp_down(0), 
-  ramp_length(0), tone_phase(0), tone_incr(0),
-  tone_type(0), tone_freq(0)
+  AudioStream(0,NULL), 
+  tone_freq(0), tone_phase(0), tone_incr(0), tone_type(0),
+  ramp_down(0), ramp_up(0), ramp_length(0)
   { 
   }
   // Change the frequency on-the-fly to permit a phase-continuous