scsi: target: iscsi: Fix np_ip_proto and np_sock_type in iscsit_setup_np

In the switch, np_ip_proto and np_sock_type set different values according
to np_network_transport, and then uniformly assign values, so the previous
values are overwritten.

Signed-off-by: tangwenji <tang.wenji@zte.com.cn>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>