d36d68161517 makes x11-wm/sway hang on start

Hi,

x11-wm/sway session will hang after start if it was launched with
seatd in a vt on a recent main with the
https://cgit.freebsd.org/src/commit/?id=d36d6816151705907393889d661cbfd25c630ca8
commit. I also run gl=mesa-devel if it matters.

Applying the fix from https://reviews.freebsd.org/D29623 unbreaks sway.