Delay value calculated incorrectly in lock_wait() if passed as float

Here is what is currently in lock_wait():

function lock_wait($name, $delay = 30) {
  $delay = (int) $delay * 1000000;
  // Begin sleeping at 25ms.
  $sleep = 25000;

Currently, PHP will cast any $delay value as an integer before it ever has a chance to be multiplied by 1 million, causing delay values such as '1.5' to round down and produce unexpected results.

function lock_wait($name, $delay = 30) {
  $delay = (int) ($delay * 1000000);
  // Begin sleeping at 25ms.
  $sleep = 25000;

Adding parenthesis around the values to be multiplied fixes this. This is already an issue in core: https://drupal.org/node/2096259.