When turning merging origin into non-merging origin, there is bad sequence:
snapshots are suspended, new origin is created, snapshots are resumed, new
origin is resumed. So it allocates memory while suspended.
To fix it, move vg_commit after suspend_lv, so that the suspend code will
treat it as precommitted vg and will preload new origin prior to suspend.
NOTE: agk doesn't like this "hack"; need to revisit and fix