use correct device when polyfilling deprecated `HMDVRDevice` (fixes #88)
use correct device when polyfilling deprecated `HMDVRDevice` (fixes #88)

jsantell/webvr-polyfill,bkkl/bkkl.github.io,bkkl/bkkl.github.io,immersive-web/webvr-polyfill,marciot/webvr-polyfill,borismus/webvr-polyfill,marciot/webvr-polyfill,jsantell/webvr-polyfill,jzitelli/webvr-polyfill,jzitelli/webvr-polyfill,borismus/webvr-polyfill,immersive-web/webvr-polyfill