Add dummy callback when removing tmp files

Author: kcwiakala

lib/uploadhandler.js

@@ -163,7 +163,7 @@ module.exports = function (options) {
                 _.each(tmpFiles, function (file) {
                     var fileInfo = map[path.basename(file)];
                     self.emit('abort', fileInfo);
-                    fs.unlink(file);
+                    fs.unlink(file, function(e) {});
                 });
             })
             .on('error', function (e) {