tests/Makefile: use test db var instead of repeating the path

Change-Id: I9859b522b5ffa7f2c9ed33ab849199d4b4e6696c
diff --git a/tests/Makefile.am b/tests/Makefile.am
index e71a250..2dba6a1 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -54,7 +54,7 @@
 	sqlite3 $(VTY_TEST_DB) < $(top_srcdir)/sql/hlr.sql
 	osmo_verify_transcript_vty.py -v \
 		-n OsmoHLR -p 4258 \
-		-r "$(top_builddir)/src/osmo-hlr -c $(top_srcdir)/doc/examples/osmo-hlr.cfg -l hlr_vty_test.db" \
+		-r "$(top_builddir)/src/osmo-hlr -c $(top_srcdir)/doc/examples/osmo-hlr.cfg -l $(VTY_TEST_DB)" \
 		$(U) $(srcdir)/*.vty
 	-rm -f $(VTY_TEST_DB)
 
@@ -69,7 +69,7 @@
 	sqlite3 $(CTRL_TEST_DB) < $(srcdir)/test_subscriber.sql
 	osmo_verify_transcript_ctrl.py -v \
 		-p 4259 \
-		-r "$(top_builddir)/src/osmo-hlr -c $(top_srcdir)/doc/examples/osmo-hlr.cfg -l hlr_ctrl_test.db" \
+		-r "$(top_builddir)/src/osmo-hlr -c $(top_srcdir)/doc/examples/osmo-hlr.cfg -l $(CTRL_TEST_DB)" \
 		$(U) $(srcdir)/*.ctrl
 	-rm -f $(CTRL_TEST_DB)