Remove unnecessary '..'.

Author: bobbens

main.lua

@@ -255,7 +255,7 @@ for i = 1, opt.num_iters do
         if opt.display_interval > 0 and i % opt.display_interval == 0 then
             image.display(output)
         end
-        image.save(paths.concat(frames_dir, string.format('%04d',i) .. '.jpg'), output)
+        image.save(paths.concat(frames_dir, string.format('%04d.jpg',i)), output)
     end
 end