Fix inability to split RAID1 image while specifying a particular PV.

Fix inability to split RAID1 image while specifying a particular PV.

The logic for resuming the original and newly split LVs was not properly
done to handle situations where anything but the last device in the array
was split.  It did not take into account the possible name collisions that
might occur when the original LV undergoes the shifting and renaming of its
sub-LVs.