TbfTest: Reset MS timeout to 0 in test_tbf_dl_llc_loss()

The timeout is set to a high value to avoid freeing the MS during main
loop iteration. Let's set it back to 0 to have a common free path in
test infrastructure.

Change-Id: I6dc4765163fde1a46574b49f3185aea65391e0d0

tests/tbf/TbfTest.cpp

@@ -622,6 +622,8 @@ static void test_tbf_dl_llc_loss()
 
 	fprintf(stderr, "=== end %s ===\n", __func__);
 
+	/* Restore MS release timeout to 0 to make sure it is freed immediately: */
+	ms_set_timeout(ms, 0);
 	TALLOC_FREE(the_pcu);
 }