tipc: remove redundant memset and stale comment from subscr.c

Eliminate code to zero-out the main topology service structure,
which is already zeroed-out.

Get rid of a comment documenting a field of the main topology
service structure that no longer exists.

Both are cosmetic changes with no impact on runtime behaviour.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

net/tipc/subscr.c

@@ -56,7 +56,6 @@ struct tipc_subscriber {
 
 /**
  * struct top_srv - TIPC network topology subscription service
- * @user_ref: TIPC userid of subscription service
  * @setup_port: reference to TIPC port that handles subscription requests
  * @subscription_count: number of active subscriptions (not subscribers!)
  * @subscriber_list: list of ports subscribing to service
@@ -535,7 +534,6 @@ int tipc_subscr_start(void)
 	struct tipc_name_seq seq = {TIPC_TOP_SRV, TIPC_TOP_SRV, TIPC_TOP_SRV};
 	int res;
 
-	memset(&topsrv, 0, sizeof(topsrv));
 	spin_lock_init(&topsrv.lock);
 	INIT_LIST_HEAD(&topsrv.subscriber_list);