ctdb-tests: Strengthen node state checking in ctdb disable/enable test

ctdb-tests: Strengthen node state checking in ctdb disable/enable test

Check that the desired state is set on all nodes instead of just the
test node.  This ensures that node flags have correctly propagated
across the cluster.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14513
Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>
Autobuild-User(master): Amitay Isaacs <amitay@samba.org>
Autobuild-Date(master): Tue Oct  6 04:32:06 UTC 2020 on sn-devel-184