OS Design: invert new and old name
OS Design: invert new and old name

Internally in ganeti we already have renamed the instance, so it's
better to pass the new name in INSTANCE_NAME and the old one in
OLD_INSTANCE_NAME rather than the old name in INSTANCE_NAME and the new
one in NEW_INSTANCE_NAME as this reflects what the cluster thinks.

Reviewed-by: iustinp


yiannist/ganeti,apyrgio/snf-ganeti,andir/ganeti,mbakke/ganeti,leshchevds/ganeti,grnet/snf-ganeti,apyrgio/ganeti,yiannist/ganeti,dimara/ganeti,dimara/ganeti,grnet/snf-ganeti,ganeti/ganeti,leshchevds/ganeti,onponomarev/ganeti,bitemyapp/ganeti,yiannist/ganeti,mbakke/ganeti,onponomarev/ganeti,bitemyapp/ganeti,andir/ganeti,andir/ganeti,ganeti/ganeti,ganeti-github-testing/ganeti-test-1,ganeti/ganeti,ganeti-github-testing/ganeti-test-1,mbakke/ganeti,apyrgio/snf-ganeti,leshchevds/ganeti,apyrgio/ganeti