screen-share: Name the seat "screen-share"

Name the seat created by the screen share plugin "screen-share" instead of
"default", to make it easier to recognize. No functional change intended.

Signed-off-by: Marek Vasut <marex@denx.de>

compositor/screen-share.c

@@ -368,7 +368,7 @@ ss_seat_create(struct shared_output *so, uint32_t id)
 	if (seat == NULL)
 		return NULL;
 
-	weston_seat_init(&seat->base, so->output->compositor, "default");
+	weston_seat_init(&seat->base, so->output->compositor, "screen-share");
 	seat->output = so;
 	seat->id = id;
 	seat->parent.seat = wl_registry_bind(so->parent.registry, id,