debug/traces: user thread state events are unrelated to runtime

Those events should not be dumped with the Runtime category but this
makes no sense. This only affects the trace.rec file.

src/debug/traces/starpu_fxt.c

@@ -1776,7 +1776,7 @@ static void handle_task_submit_event(struct fxt_ev_64 *ev, struct starpu_fxt_opt
 		if (eventstr)
 		{
 			user_thread_push_state(timestamp, prefix, tid, eventstr);
-			recfmt_user_thread_push_state(timestamp, tid, eventstr, "Runtime");
+			recfmt_user_thread_push_state(timestamp, tid, eventstr, "User");
 		}
 		else
 		{