lvmlockd: remove all LVM activation code

"clvm" RA use activate_vgs option to activate all volume groups on
system, and the default value of activate_vgs is true. I followed
it in lvmlockd. But now, I realized the idea is just wrong.

lvmlockd RA should only manage the lvmlockd daemon, and don't do
anything about activation. Instead, all activation work should be
done in the LVM-activation RA. David Teigland also agrees on this
change.

Signed-off-by: Eric Ren <zren@suse.com>