Fix minification build error in SphereBufferGeometry.js

src/extras/geometries/SphereBufferGeometry.js

@@ -40,7 +40,7 @@ THREE.SphereBufferGeometry = function ( radius, widthSegments, heightSegments, p
 	var uvs = new THREE.InterleavedBufferAttribute( vertexBuffer, 2, 6 );
 	this.addAttribute( 'uv', uvs );
 
-	var x, y, u, v, px, py, px, index = 0, vertices = [], normal = new THREE.Vector3();
+	var x, y, u, v, px, py, pz, index = 0, vertices = [], normal = new THREE.Vector3();
 
 	for ( y = 0; y <= heightSegments; y ++ ) {
 
@@ -73,7 +73,7 @@ THREE.SphereBufferGeometry = function ( radius, widthSegments, heightSegments, p
 	}
 
 	var indices = [];
-	
+	var ul;
 	for ( y = 0, ul = heightSegments - 1; y < ul; y++ ) {
 
 		for ( x = 0; x < widthSegments; x++ ) {