tests: TbfTest: Unify stderr and stdout to ease debugging

osmo-pcu code is really verbose, and since log lines printing start and
end of tests are sent to a different file, it's really difficult to
understand which test outputs what.

Change-Id: I3e887158e2c9585c360d44f12f995f55861170f2
diff --git a/tests/testsuite.at b/tests/testsuite.at
index 09b0247..8a319bd 100644
--- a/tests/testsuite.at
+++ b/tests/testsuite.at
@@ -24,9 +24,8 @@
 
 AT_SETUP([tbf])
 AT_KEYWORDS([tbf])
-cat $abs_srcdir/tbf/TbfTest.ok > expout
 cat $abs_srcdir/tbf/TbfTest.err > experr
-AT_CHECK([$OSMO_QEMU $abs_top_builddir/tests/tbf/TbfTest], [0], [expout], [experr])
+AT_CHECK([$OSMO_QEMU $abs_top_builddir/tests/tbf/TbfTest], [0], [ignore], [experr])
 AT_CLEANUP
 
 AT_SETUP([bitcomp])