make PR compile in MSVC6

stb_dxt.h

@@ -427,15 +427,20 @@ static const float midpoints6[64] = {
    0.772549f, 0.788235f, 0.803922f, 0.819608f, 0.835294f, 0.850980f, 0.866667f, 0.882353f, 0.898039f, 0.913725f, 0.929412f, 0.945098f, 0.960784f, 0.976471f, 0.992157f, 1.0f
 };
 
-static unsigned short stb__Quantize5(float x) {
+static unsigned short stb__Quantize5(float x)
+{
+   unsigned short q;
    x = x < 0 ? 0 : x > 1 ? 1 : x;  // saturate
-    unsigned short q = (unsigned short)(x * 31);
+   q = (unsigned short)(x * 31);
    q += (x > midpoints5[q]);
    return q;
 }
-static unsigned short stb__Quantize6(float x) {
+
+static unsigned short stb__Quantize6(float x)
+{
+   unsigned short q;
    x = x < 0 ? 0 : x > 1 ? 1 : x;  // saturate
-    unsigned short q = (unsigned short)(x * 63);
+   q = (unsigned short)(x * 63);
    q += (x > midpoints6[q]);
    return q;
 }