flightrecorder: Don't subscribe by default to the drm-backend

As the flight recorder subscribed by default to the drm-backend will
implicily arm the KMS page flip counter. Just use the "log", log scope.

To make this more obvious, with this change we also print the
subscriptions, when we detect that the flight recorder is enabled.

Users can use the provided cmd line args (-f/--flight-rec-scopes) to
adjust those.

Signed-off-by: Marius Vlad <marius.vlad@collabora.com>

frontend/main.c

@@ -74,7 +74,7 @@
 #define WINDOW_TITLE "Weston Compositor"
 /* flight recorder size (in bytes) */
 #define DEFAULT_FLIGHT_REC_SIZE (5 * 1024 * 1024)
-#define DEFAULT_FLIGHT_REC_SCOPES "log,drm-backend"
+#define DEFAULT_FLIGHT_REC_SCOPES "log"
 
 struct wet_output_config {
 	int width;
@@ -4586,7 +4586,11 @@ wet_main(int argc, char *argv[], const struct weston_testsuite_data *test_data)
 	free(cmdline);
 	log_uname();
 
-	weston_log("Flight recorder: %s\n", flight_rec ? "enabled" : "disabled");
+	weston_log("Flight recorder: %s", flight_rec ? "enabled" : "disabled");
+	if (flight_rec)
+		weston_log_continue(", scopes subscribed: %s", flight_rec_scopes);
+
+	weston_log_continue("\n");
 	verify_xdg_runtime_dir();
 
 	display = wl_display_create();