target: Add TFO->put_session() caller for HW fabric session shutdown

This patch adds an optional target_core_fabric_ops->put_session() caller
within the existing target_put_session() code path.

This is required by tcm_qla2xxx code in order to invoke it's own fabric
specific session shutdown handler using se_session->sess_kref.

Signed-off-by: Joern Engel <joern@logfs.org>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Arun Easi <arun.easi@qlogic.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

include/target/target_core_fabric.h

@@ -47,6 +47,7 @@ struct target_core_fabric_ops {
 	 */
 	int (*check_stop_free)(struct se_cmd *);
 	void (*release_cmd)(struct se_cmd *);
+	void (*put_session)(struct se_session *);
 	/*
 	 * Called with spin_lock_bh(struct se_portal_group->session_lock held.
 	 */