tests/tbf: Set up pcu timers in prepare_pcu()

Change-Id: I30a491f82cced558ad72108c3c5ed7015d1d4d3b
diff --git a/tests/tbf/TbfTest.cpp b/tests/tbf/TbfTest.cpp
index d077852..4651269 100644
--- a/tests/tbf/TbfTest.cpp
+++ b/tests/tbf/TbfTest.cpp
@@ -67,6 +67,8 @@
 {
 	struct gprs_pcu *pcu = gprs_pcu_alloc(tall_pcu_ctx);
 	bssgp_set_bssgp_callback(gprs_gp_send_test_cb, NULL);
+	osmo_tdef_set(pcu->T_defs, -2030, 0, OSMO_TDEF_S);
+	osmo_tdef_set(pcu->T_defs, -2031, 0, OSMO_TDEF_S);
 	return pcu;
 }
 
@@ -190,10 +192,7 @@
 	the_pcu->alloc_algorithm = alloc_algorithm_a;
 	bts->initial_cs_dl = cs;
 	bts->initial_cs_ul = cs;
-	osmo_tdef_set(the_pcu->T_defs, -2030, 0, OSMO_TDEF_S);
-	osmo_tdef_set(the_pcu->T_defs, -2031, 0, OSMO_TDEF_S);
 	trx = &bts->trx[0];
-
 	trx->pdch[ts_no].enable();
 	bts_set_current_frame_number(bts, DUMMY_FN);
 }