This patch is fixing the cleanup_nodes.sh script to take in account
undefining nodes with NVRAM set (UEFI mode). The --nvram option is now
being passed to the "virsh undefine" command, this will undefine nodes
with (and without) NVRAM set.
Change-Id: Idbc2d0d1765cad969e68544109bd44963cadc06c
Closes-Bug: #1659335