rxrpc: Add a tracepoint for the call timer

Add a tracepoint to log call timer initiation, setting and expiry.

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

net/rxrpc/misc.c

@@ -194,3 +194,11 @@ const char rxrpc_rtt_rx_traces[rxrpc_rtt_rx__nr_trace][5] = {
 	[rxrpc_rtt_rx_ping_response]	= "PONG",
 	[rxrpc_rtt_rx_requested_ack]	= "RACK",
 };
+
+const char rxrpc_timer_traces[rxrpc_timer__nr_trace][8] = {
+	[rxrpc_timer_begin]			= "Begin ",
+	[rxrpc_timer_expired]			= "*EXPR*",
+	[rxrpc_timer_set_for_ack]		= "SetAck",
+	[rxrpc_timer_set_for_send]		= "SetTx ",
+	[rxrpc_timer_set_for_resend]		= "SetRTx",
+};