libudev: set errno when udev_device_new_from_* or udev_device_get_parent_* fail
Revert "networkd: don't assume udev_device_new_from_device_id sets errno"

libudev now does set errno correctly, so we can indeed rely on this.

This reverts commit 2b49732c3d511007ae2c413997e56c40f678d79a.