We shouldn't fail when finding an unnamed bitmap in a unnamed node or
node with auto-generated node name, as bitmap migration ignores such
bitmaps in the first place.
Fixes: 82640edb88faa
Fixes: 4ff5cc121b089
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200626130658.76498-1-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: commit message grammar tweaks]
Signed-off-by: Eric Blake <eblake@redhat.com>