tmfiles: change need dev to use dev.
tmfiles: change need dev to use dev.

This is being changed to use for the reason I stated in the previous
commit. There is no guarantee that someone is using a device manager.

OpenRC/openrc,williamh/openrc,dwfreed/openrc,williamh/openrc,OpenRC/openrc,OpenRC/openrc,williamh/openrc,dwfreed/openrc,dwfreed/openrc