Don't double-terminate a display. Some dEQP tests call eglTerminate twice on the same display and cause crashes. BUG=angleproject:2546 Change-Id: I3118e07aec19a28ad2b76fc2705be5b0bea37857 Reviewed-on: https://chromium-review.googlesource.com/1066467 Reviewed-by: Geoff Lang <geofflang@chromium.org> Commit-Queue: Geoff Lang <geofflang@chromium.org>