Fix build if libinput isn't present
Created by: MarkusVolk
Since libinput is an optional dependency the libinput backend is possibly undeclared. wlr_backend_destroy(backend) below will clean up the child libinput backend if any.
Due to an influx of spam, we have had to impose restrictions on new accounts. Please see this wiki page for instructions on how to get full permissions. Sorry for the inconvenience.
Created by: MarkusVolk
Since libinput is an optional dependency the libinput backend is possibly undeclared. wlr_backend_destroy(backend) below will clean up the child libinput backend if any.