This change is proposed again, avoiding lsblk features missing from
older distros:
- lsblk is avoided entirely for a whole-disk image with a single
partition, which would be the majority of old image building jobs
- Field PARTTYPENAME not available on the lsblk in CentOS-8, instead
rely on the GUID being correct for EFI partitions
- Argument --output-all not available on the lsblk in CentOS-7, this
is just for logging debug, so can be removed
This reverts commit b06bac734c.
Change-Id: Ib0d4e7751fd968511fc7f672d524e58d1488ae11
41c21e91db