Fixed compile error introduced in #1267

(ERROR - variable instance_material is undeclared)

src/extras/loaders/ColladaLoader.js

@@ -734,14 +734,14 @@ THREE.ColladaLoader = function () {
 
 					for ( j = 0; j < instance_materials.length; j ++ ) {
 
-						var inst_material = instance_materials[j];
-						var mat = materials[instance_material.target];
+						var instance_material = instance_materials[ j ];
+						var mat = materials[ instance_material.target ];
 						var effect_id = mat.instance_effect.url;
-						var shader = effects[effect_id].shader;
+						var shader = effects[ effect_id ].shader;
 
 						shader.material.opacity = !shader.material.opacity ? 1 : shader.material.opacity;
-						used_materials[inst_material.symbol] = num_materials;
-						used_materials_array.push(shader.material)
+						used_materials[ instance_material.symbol ] = num_materials;
+						used_materials_array.push( shader.material )
 						first_material = shader.material;
 						first_material.name = mat.name == null || mat.name === '' ? mat.id : mat.name;
 						num_materials ++;