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/Makefile.am b/tests/Makefile.am
index 42dade9..c599636 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -138,7 +138,7 @@
 	testsuite.at $(srcdir)/package.m4 $(TESTSUITE)	\
 	rlcmac/RLCMACTest.ok rlcmac/RLCMACTest.err \
 	alloc/AllocTest.ok alloc/AllocTest.err \
-	tbf/TbfTest.ok tbf/TbfTest.err \
+	tbf/TbfTest.err \
 	bitcomp/BitcompTest.ok bitcomp/BitcompTest.err \
 	types/TypesTest.ok types/TypesTest.err \
 	ms/MsTest.ok ms/MsTest.err alloc/MslotTest.ok \