Fix: EEVEE: Wrong subsurface sample distribution

The sample distribution was biased toward 0, which
created sharper details than expected.

However the downside is that the subsurface is now
more jittery because of the low amount of samples.

source/blender/draw/engines/eevee_next/eevee_subsurface.cc

@@ -116,8 +116,7 @@ void SubsurfaceModule::precompute_samples_location()
   double golden_angle = M_PI * (3.0 - sqrt(5.0));
   for (auto i : IndexRange(data_.sample_len)) {
     float theta = golden_angle * i + M_PI * 2.0f * rand_u;
-    /* Scale using rand_v in order to keep first sample always at center. */
-    float x = (1.0f + (rand_v / data_.sample_len)) * (i / float(data_.sample_len));
+    float x = (rand_v + i) / data_.sample_len;
     float r = SubsurfaceModule::burley_sample(d, x);
     data_.samples[i].x = cosf(theta) * r;
     data_.samples[i].y = sinf(theta) * r;