cilium: don't try to mount sys/fs/bpf if already mounted
cilium: don't try to mount sys/fs/bpf if already mounted

systemd v238 already includes the mount, and the unit file fails.  We
test for the existence of the mount, rather than testing systemd
versions directly.

robinpercy/kops,justinsb/kops,justinsb/kops,kubernetes/kops,justinsb/kops,robinpercy/kops,kubernetes/kops,robinpercy/kops,robinpercy/kops,kubernetes/kops