MFC r338223, r338263: Missing bits from OptionalObsoleteFiles

r338223:
Remove ZFS leftovers when WITHOUT_ZFS is set

Submitted by: Oliver Pinter
Differential Revision: https://reviews.freebsd.org/D16810

r338263:
Remove hyper-v leftovers when WITHOUT_HYPERV is set

hv_vss_daemon was missed.