rxrpc: Add some more tracing

Add the following extra tracing information:

 (1) Modify the rxrpc_transmit tracepoint to record the Tx window size as
     this is varied by the slow-start algorithm.

 (2) Modify the rxrpc_rx_ack tracepoint to record more information from
     received ACK packets.

 (3) Add an rxrpc_rx_data tracepoint to record the information in DATA
     packets.

 (4) Add an rxrpc_disconnect_call tracepoint to record call disconnection,
     including the reason the call was disconnected.

 (5) Add an rxrpc_improper_term tracepoint to record implicit termination
     of a call by a client either by starting a new call on a particular
     connection channel without first transmitting the final ACK for the
     previous call.

Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c
index e1e83af..b0ecb77 100644
--- a/net/rxrpc/conn_object.c
+++ b/net/rxrpc/conn_object.c
@@ -173,6 +173,7 @@ void __rxrpc_disconnect_call(struct rxrpc_connection *conn,
 		/* Save the result of the call so that we can repeat it if necessary
 		 * through the channel, whilst disposing of the actual call record.
 		 */
+		trace_rxrpc_disconnect_call(call);
 		chan->last_service_id = call->service_id;
 		if (call->abort_code) {
 			chan->last_abort = call->abort_code;