Move timer X2001 to tbf_fsm

The side effect is that the timer is enabled for other scenarios where a
PACCH assignment happens, like an Assignment Reject or Ul Assignment
(that's why there's more lines showing up now in TbfTest.err).

Change-Id: Ib8ab2f7397ad05c6fcd5dd74af55a1e2c56e1463
diff --git a/tests/tbf/TbfTest.cpp b/tests/tbf/TbfTest.cpp
index ce5f784..9ba1753 100644
--- a/tests/tbf/TbfTest.cpp
+++ b/tests/tbf/TbfTest.cpp
@@ -3182,6 +3182,7 @@
 	fprintf(stderr, "=== start %s ===\n", __func__);
 
 	setup_bts(bts, ts_no, 4);
+	OSMO_ASSERT(osmo_tdef_set(the_pcu->T_defs, -2000, 0, OSMO_TDEF_MS) == 0);
 
 	int rc = 0;
 
@@ -3198,8 +3199,7 @@
 		trx_no, ts_no, fn, bn);
 
 	OSMO_ASSERT(rc == 0);
-
-	ul_tbf->handle_timeout();
+	osmo_select_main(0);
 
 	TALLOC_FREE(the_pcu);
 	fprintf(stderr, "=== end %s ===\n", __func__);