Merge remote-tracking branch 'remotes/dgilbert/tags/pull-migration-20200928a' into staging

Migration: Revert one patch for 068 fix

One patch in the last pull broke test 068 which
does a pair of vmload's.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

# gpg: Signature made Mon 28 Sep 2020 16:19:17 BST
# gpg:                using RSA key 45F5C71B4A0CB7FB977A9FA90516331EBC5BFDE7
# gpg: Good signature from "Dr. David Alan Gilbert (RH2) <dgilbert@redhat.com>" [full]
# Primary key fingerprint: 45F5 C71B 4A0C B7FB 977A  9FA9 0516 331E BC5B FDE7

* remotes/dgilbert/tags/pull-migration-20200928a:
  Revert "migration: Properly destroy variables on incoming side"

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>