nvme-tcp: send only permitted commands for secure concat

In addition to sending permitted commands such as connect/auth
over the initial unencrypted admin connection as part of secure
channel concatenation, the host also sends commands such as
Property Get and Identify on the same. This is a spec violation
leading to secure concat failures. Fix this by ensuring these
additional commands are avoided on this connection.

Fixes: 104d0e2f ("nvme-fabrics: reset admin connection for secure concatenation")
Signed-off-by: Martin George <marting@netapp.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>