manager: skip BPF cleanup if we never initialized

manager: skip BPF cleanup if we never initialized

This fixes a spurious warning from the manager running in user mode:

systemd[1668]: Reached target sockets.target.
systemd[1669]: Failed to create BPF map: Operation not permitted
systemd[1669]: Finished systemd-tmpfiles-setup.service.
systemd[1669]: Listening on dbus.socket.
systemd[1669]: Reached target sockets.target.
systemd[1669]: Reached target basic.target.
systemd[1]: Started user@6.service.

Fixes https://bugzilla.redhat.com/show_bug.cgi?id=2084955.