fix(verify_decommission): avoid to check nodes status from decommission node
fix(verify_decommission): avoid to check nodes status from decommission node

It's harmless to check nodes status from decommission node, the status
can be get by retry.

This patch changed to only check nodes status from undecommission nodes.

Signed-off-by: Amos Kong <eb01d8f828a6c9a20be4534e72e049aaf41503df@scylladb.com>

scylladb/scylla-cluster-tests,scylladb/scylla-longevity-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-longevity-tests,scylladb/scylla-cluster-tests,scylladb/scylla-longevity-tests