Target/iscsi: Fix sendtargets response pdu for iser transport

In case the transport is iser we should not include the
iscsi target info in the sendtargets text response pdu.
This causes sendtargets response to include the target
info twice.

Modify iscsit_build_sendtargets_response to filter
transport types that don't match.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Reported-by: Slava Shwartsman <valyushash@gmail.com>
Cc: stable@vger.kernel.org # 3.11+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>