update.php - wrong count in fieldset title

My UI patch for update.php introduced a new core bug - it reports the wrong count of pending updates in the fieldset title. I was using an array called $all to track a count. This patch uses an integer so the addition bug is easily squashed.

To test this, I suggest adding two updates to your favorite .nstall file and noticing that with the patch you get two and without the patch you get - something one.