Coding standards Clean Up

1. $uid = $user->id();, is not used in the further code.
2. made changes for few misspells.

3. _autologout_get_user_timeout(); is getting the user timeout, but the user time out is not been used in the code base.

/**
 * Adds a field to user/edit to change that users logout.
 */
function autologout_form_user_form_alter(&$form, FormStateInterface $form_state) {
  $user_timeout = _autologout_get_user_timeout();

4. similar to 3 point, $route is not been used in the further code base.

/**
 * Implements hook_autologout_refresh_only().
 */
function autologout_autologout_refresh_only() {
  $url = Url::fromRoute('<current>');
  $route = explode('/', $url->toString());