target: Drop config_item_name usage in fabric TFO->free_wwn()

This patch removes config_item_name() informational usage of
TFO->free_wwn() treewide in loopback, tcm_fc, ib_srpt and
tcm_vhost module code.

Using v4 target_core_fabric_configfs.c logic, a fabric call for
config_item_name() in TFO->drop_wwn() context returns NULL as
target_fabric_drop_wwn() invoking config_item_put() ->
config_group_put() will release fabric_port->port_wwn.wwn_group
before the last config_item_put() -> TFO->drop_wwn() is
invoked.

Reported-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/tcm_fc/tfc_conf.c

@@ -436,8 +436,7 @@ static void ft_del_lport(struct se_wwn *wwn)
 	struct ft_lport_acl *lacl = container_of(wwn,
 				struct ft_lport_acl, fc_lport_wwn);
 
-	pr_debug("del lport %s\n",
-			config_item_name(&wwn->wwn_group.cg_item));
+	pr_debug("del lport %s\n", lacl->name);
 	mutex_lock(&ft_lport_lock);
 	list_del(&lacl->list);
 	mutex_unlock(&ft_lport_lock);