rpi: seat quick fix

Fix the default seat name, so that we can find the input devices by
default.

This is just a quick fix. Further enhancement would be to make the
default seat on rpi taken from a command line option like the other
backends do. Furthermore, udev_input_init() should accept NULL as seat
to use the default seat, avoiding us hardcoding "seat0" all over.

Cc: Jonas Ådahl <jadahl@gmail.com>
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

src/compositor-rpi.c

@@ -513,7 +513,7 @@ rpi_compositor_create(struct wl_display *display, int *argc, char *argv[],
 
 	if (udev_input_init(&compositor->input,
 			    &compositor->base,
-			    compositor->udev, "ID_SEAT") != 0) {
+			    compositor->udev, "seat0") != 0) {
 		weston_log("Failed to initialize udev input.\n");
 		goto out_udev;
 	}