rxrpc: Trace packet transmission

Trace successful packet transmission (kernel_sendmsg() succeeded, that is)
in AF_RXRPC.  We can share the enum that defines the transmission points
with the trace_rxrpc_tx_fail() tracepoint, so rename its constants to be
applicable to both.

Also, save the internal call->debug_id in the rxrpc_channel struct so that
it can be used in retransmission trace lines.

Signed-off-by: David Howells <dhowells@redhat.com>

net/rxrpc/local_event.c

@@ -72,7 +72,10 @@ static void rxrpc_send_version_request(struct rxrpc_local *local,
 	ret = kernel_sendmsg(local->socket, &msg, iov, 2, len);
 	if (ret < 0)
 		trace_rxrpc_tx_fail(local->debug_id, 0, ret,
-				    rxrpc_tx_fail_version_reply);
+				    rxrpc_tx_point_version_reply);
+	else
+		trace_rxrpc_tx_packet(local->debug_id, &whdr,
+				      rxrpc_tx_point_version_reply);
 
 	_leave("");
 }