cosmetic: TbfTest: fix typo in comment

Change-Id: I35bb28c5669747823b0dfebe27ecd7a5a0c5d60f
diff --git a/tests/tbf/TbfTest.cpp b/tests/tbf/TbfTest.cpp
index 0205f2b..643551b 100644
--- a/tests/tbf/TbfTest.cpp
+++ b/tests/tbf/TbfTest.cpp
@@ -2525,7 +2525,7 @@
 	osmo_fsm_inst_dispatch(ms_dl_tbf(second_ms)->state_fi, TBF_EV_ASSIGN_PCUIF_CNF, NULL);
 	osmo_select_main(0);
 
-	/* get the PACCH PktDlAss for the DL-TBF, allocated one the UL-TBF from the new MS obj: */
+	/* get the PACCH PktDlAss for the DL-TBF, allocated on the UL-TBF from the new MS obj: */
 	request_dl_rlc_block(dl_tbf->bts, dl_tbf->control_ts, &fn);
 
 	fprintf(stderr, "=== end %s ===\n", __func__);