rxrpc: Create a null security type and get rid of conditional calls

Create a null security type for security index 0 and get rid of all
conditional calls to the security operations.  We expect normally to be
using security, so this should be of little negative impact.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/rxrpc/ar-connection.c b/net/rxrpc/ar-connection.c
index 9b69667..97f4fae 100644
--- a/net/rxrpc/ar-connection.c
+++ b/net/rxrpc/ar-connection.c
@@ -207,6 +207,7 @@
 		INIT_LIST_HEAD(&conn->bundle_link);
 		conn->calls = RB_ROOT;
 		skb_queue_head_init(&conn->rx_queue);
+		conn->security = &rxrpc_no_security;
 		rwlock_init(&conn->lock);
 		spin_lock_init(&conn->state_lock);
 		atomic_set(&conn->usage, 1);
@@ -564,8 +565,7 @@
 		     candidate->debug_id, candidate->trans->debug_id);
 
 		rxrpc_assign_connection_id(candidate);
-		if (candidate->security)
-			candidate->security->prime_packet_security(candidate);
+		candidate->security->prime_packet_security(candidate);
 
 		/* leave the candidate lurking in zombie mode attached to the
 		 * bundle until we're ready for it */
@@ -830,7 +830,10 @@
 	ASSERT(RB_EMPTY_ROOT(&conn->calls));
 	rxrpc_purge_queue(&conn->rx_queue);
 
-	rxrpc_clear_conn_security(conn);
+	conn->security->clear(conn);
+	key_put(conn->key);
+	key_put(conn->server_key);
+
 	rxrpc_put_transport(conn->trans);
 	kfree(conn);
 	_leave("");