Refactor code rejecting UL-TBF upon rx of PktResourceReq

* Make it similar to the already existing TBF allocation procedures
* Pass pdch pointer instead of trx and ts numbers

Change-Id: I04b3b65942732cc652adeaa507529b849292ff61
diff --git a/tests/tbf/TbfTest.cpp b/tests/tbf/TbfTest.cpp
index 314d2d9..80dfc2f 100644
--- a/tests/tbf/TbfTest.cpp
+++ b/tests/tbf/TbfTest.cpp
@@ -3240,7 +3240,7 @@
 
 	ms = bts_alloc_ms(bts, 0, 0);
 	ms_set_tlli(ms, tlli);
-	ul_tbf = handle_tbf_reject(bts, ms, trx_no, ts_no);
+	ul_tbf = ms_new_ul_tbf_rejected_pacch(ms, &bts->trx[trx_no].pdch[ts_no]);
 
 	OSMO_ASSERT(ul_tbf != 0);