target: Remove write-only stats fields and lock from struct se_node_acl

Commit 04f3b31bff72 ("iscsi-target: Convert iscsi_session statistics to
atomic_long_t") removed the updating of these fields in iscsi (the only
fabric driver that ever touched these counters), and the core has no way
to report or otherwise use the values.  Remove the last remnants of
these counters.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_tpg.c

@@ -278,7 +278,6 @@ struct se_node_acl *core_tpg_check_initiator_node_acl(
 	snprintf(acl->initiatorname, TRANSPORT_IQN_LEN, "%s", initiatorname);
 	acl->se_tpg = tpg;
 	acl->acl_index = scsi_get_new_index(SCSI_AUTH_INTR_INDEX);
-	spin_lock_init(&acl->stats_lock);
 	acl->dynamic_node_acl = 1;
 
 	tpg->se_tpg_tfo->set_default_node_attributes(acl);
@@ -406,7 +405,6 @@ struct se_node_acl *core_tpg_add_initiator_node_acl(
 	snprintf(acl->initiatorname, TRANSPORT_IQN_LEN, "%s", initiatorname);
 	acl->se_tpg = tpg;
 	acl->acl_index = scsi_get_new_index(SCSI_AUTH_INTR_INDEX);
-	spin_lock_init(&acl->stats_lock);
 
 	tpg->se_tpg_tfo->set_default_node_attributes(acl);
 

include/target/target_core_base.h

@@ -517,10 +517,6 @@ struct se_node_acl {
 	u32			acl_index;
 #define MAX_ACL_TAG_SIZE 64
 	char			acl_tag[MAX_ACL_TAG_SIZE];
-	u64			num_cmds;
-	u64			read_bytes;
-	u64			write_bytes;
-	spinlock_t		stats_lock;
 	/* Used for PR SPEC_I_PT=1 and REGISTER_AND_MOVE */
 	atomic_t		acl_pr_ref_count;
 	struct se_dev_entry	**device_list;