rfc3720 indicates that SendTargets on discovery *and* normal operational
sessions must be supported by targets:
A system that contains targets MUST support discovery sessions on
each of its iSCSI IP address-port pairs, and MUST support the
SendTargets command on the discovery session.
...
A target MUST support the SendTargets command on operational
sessions...
Signed-off-by: David Disseldorp <ddiss@suse.de>