LVM CLI exiting with exit code 5 after snapshot resize with no requested change

[trgill]

Edit: it only happens when no size change is required

update code that estimates extend required to round the request to a physical extent

[root@fedora snapshot]# lvextend -L 10551296B vg1/lv2_vg1_snapset1
  Rounding size to boundary between physical extents: 12.00 MiB.
  New size (3 extents) matches existing size (3 extents).
  No size change.
[root@fedora snapshot]# echo $?
5