stb_vorbis: fix unused variables

Conflicts:
	stb_vorbis.c

stb_vorbis.c

@@ -1698,7 +1698,7 @@ static int codebook_decode_scalar(vorb *f, Codebook *c)
    #define CODEBOOK_ELEMENT_BASE(c)         (0)
 #endif
 
-static int codebook_decode_start(vorb *f, Codebook *c, int len)
+static int codebook_decode_start(vorb *f, Codebook *c)
 {
    int z = -1;
 
@@ -1720,7 +1720,7 @@ static int codebook_decode_start(vorb *f, Codebook *c, int len)
 
 static int codebook_decode(vorb *f, Codebook *c, float *output, int len)
 {
-   int i,z = codebook_decode_start(f,c,len);
+   int i,z = codebook_decode_start(f,c);
    if (z < 0) return FALSE;
    if (len > c->dimensions) len = c->dimensions;
 
@@ -1759,7 +1759,7 @@ static int codebook_decode(vorb *f, Codebook *c, float *output, int len)
 
 static int codebook_decode_step(vorb *f, Codebook *c, float *output, int len, int step)
 {
-   int i,z = codebook_decode_start(f,c,len);
+   int i,z = codebook_decode_start(f,c);
    float last = CODEBOOK_ELEMENT_BASE(c);
    if (z < 0) return FALSE;
    if (len > c->dimensions) len = c->dimensions;
@@ -2628,7 +2628,6 @@ static __forceinline void iter_54(float *z)
 
 static void imdct_step3_inner_s_loop_ld654(int n, float *e, int i_off, float *A, int base_n)
 {
-   int k_off = -8;
    int a_off = base_n >> 3;
    float A2 = A[0+a_off];
    float *z = e + i_off;