Fix UUM-74749: APV Rendering Layers error when using mesh with multiple submeshes

JIRA: https://jira.unity3d.com/browse/UUM-74749

Author: YvainRaeymaekers

Packages/com.unity.render-pipelines.core/Editor/Lighting/ProbeVolume/ProbeGIBaking.RenderingLayers.cs

@@ -117,15 +117,11 @@ static AccelStructAdapter BuildAccelerationStructure()
                         continue;
 
                     int subMeshCount = mesh.subMeshCount;
-                    for (int i = 0; i < subMeshCount; ++i)
-                    {
-                        var matIndices = new uint[subMeshCount];
-                        Array.Fill(matIndices, renderer.component.renderingLayerMask); // repurpose the material id as we don't need it here
-                        var perSubMeshMask = new uint[subMeshCount];
-
-                        Array.Fill(perSubMeshMask, GetInstanceMask(renderer.component.shadowCastingMode));
-                        accelStruct.AddInstance(renderer.component.GetInstanceID(), renderer.component, perSubMeshMask, matIndices);
-                    }
+                    var matIndices = new uint[subMeshCount];
+                    Array.Fill(matIndices, renderer.component.renderingLayerMask); // repurpose the material id as we don't need it here
+                    var perSubMeshMask = new uint[subMeshCount];
+                    Array.Fill(perSubMeshMask, GetInstanceMask(renderer.component.shadowCastingMode));
+                    accelStruct.AddInstance(renderer.component.GetInstanceID(), renderer.component, perSubMeshMask, matIndices);
                 }
 
                 foreach (var terrain in contributors.terrains)