lvol: Fix pct of origin (#7053)
* add support for percentage of origin size for creating snapshot volumes
* add changelog fragment
* add pull request link
Co-authored-by: Felix Fontein <felix@fontein.de>
* fix what's not idempotent
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Co-authored-by: Felix Fontein <felix@fontein.de>
(cherry picked from commit a0c67a8894)
Co-authored-by: Bob Mader <bmader@redhat.com>