Bug 1041879 - Remove dead 'useNewStyle' code from shared/js/lockscreen_slide.js

Why were the order of these changed? I see your comment [1] but it's not clear why this worked in the past and not anymore.
[1] https://github.com/mozilla-b2g/gaia/pull/23666/files#diff-3fb4b6ea1cebdea57ada1ac50c2c9c7aR839