target: Drop unnecessary core_tpg_register TFO parameter

This patch drops unnecessary target_core_fabric_ops parameter usage
for core_tpg_register() during fabric driver TFO->fabric_make_tpg()
se_portal_group creation callback execution.

Instead, use the existing se_wwn->wwn_tf->tf_ops pointer to ensure
fabric driver is really using the same TFO provided at module_init
time.

Also go ahead and drop the forward TFO declarations tree-wide, and
handling the special case for iscsi-target discovery TPG.

Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index dbad5c6..cea207e 100644
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -92,7 +92,6 @@
 		 " instead of using the node_guid of the first HCA.");
 
 static struct ib_client srpt_client;
-static const struct target_core_fabric_ops srpt_template;
 static void srpt_release_channel(struct srpt_rdma_ch *ch);
 static int srpt_queue_status(struct se_cmd *cmd);
 
@@ -3733,8 +3732,7 @@
 	int res;
 
 	/* Initialize sport->port_wwn and sport->port_tpg_1 */
-	res = core_tpg_register(&srpt_template, &sport->port_wwn,
-			&sport->port_tpg_1, SCSI_PROTOCOL_SRP);
+	res = core_tpg_register(&sport->port_wwn, &sport->port_tpg_1, SCSI_PROTOCOL_SRP);
 	if (res)
 		return ERR_PTR(res);