Remove a couple unused member variables

Alc/alc.cpp

@@ -2643,8 +2643,6 @@ void AllocateVoices(ALCcontext *context, ALsizei num_voices, ALsizei old_sends)
 
             voice->mFlags = old_voice->mFlags;
 
-            voice->mOffset = old_voice->mOffset;
-
             std::copy(std::begin(old_voice->mPrevSamples), std::end(old_voice->mPrevSamples),
                 std::begin(voice->mPrevSamples));
 

Alc/alu.cpp

@@ -136,7 +136,6 @@ void ProcessHrtf(ALCdevice *device, const ALsizei SamplesToDo)
     DirectHrtfState *state{device->mHrtfState.get()};
     MixDirectHrtf(LeftOut, RightOut, device->Dry.Buffer, device->HrtfAccumData, state,
         device->Dry.NumChannels, SamplesToDo);
-    state->Offset += SamplesToDo;
 }
 
 void ProcessAmbiDec(ALCdevice *device, const ALsizei SamplesToDo)

Alc/hrtf.h

@@ -78,7 +78,6 @@ struct HrtfParams {
 
 struct DirectHrtfState {
     /* HRTF filter state for dry buffer content */
-    ALsizei Offset{0};
     ALsizei IrSize{0};
     struct ChanData {
         alignas(16) HrirArray<ALfloat> Values;

Alc/mixvoice.cpp

@@ -805,7 +805,6 @@ void MixVoice(ALvoice *voice, ALvoice::State vstate, const ALuint SourceID, ALCc
         DataPosFrac &= FRACTIONMASK;
 
         OutPos += DstBufferSize;
-        voice->mOffset += DstBufferSize;
         Counter = maxi(DstBufferSize, Counter) - DstBufferSize;
 
         if(UNLIKELY(vstate != ALvoice::Playing))

OpenAL32/Include/alu.h

@@ -249,8 +249,6 @@ struct ALvoice {
 
     ALuint mFlags;
 
-    ALuint mOffset; /* Number of output samples mixed since starting. */
-
     using ResamplePaddingArray = std::array<ALfloat,MAX_RESAMPLE_PADDING*2>;
     alignas(16) std::array<ResamplePaddingArray,MAX_INPUT_CHANNELS> mPrevSamples;