[tracker-miners/sam/functional-tests] functional-tests: Add missing var in meson build

[Sam Thursfield <sthursfield src gnome org>]

commit 04eddec60ec8e3bc168a98c225ba533dcf5a3f4c
Author: Sam Thursfield <sam afuera me uk>
Date:   Tue Jul 17 11:48:48 2018 +0200

    functional-tests: Add missing var in meson build

 tests/functional-tests/meson.build | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/tests/functional-tests/meson.build b/tests/functional-tests/meson.build
index 1a78d2860..0171b0a04 100644
--- a/tests/functional-tests/meson.build
+++ b/tests/functional-tests/meson.build
@@ -55,6 +55,7 @@ test_env.set('DCONF_PROFILE', dconf_profile_full_path)
 
 test_env.set('TRACKER_EXTRACTORS_DIR', tracker_extractors_dir)
 test_env.set('TRACKER_EXTRACTOR_RULES_DIR', tracker_extractor_rules_dir)
+test_env.set('TRACKER_FUNCTIONAL_TEST_BUILD_DIR', build_root)
 test_env.set('TRACKER_FUNCTIONAL_TEST_CONFIG', config_json_full_path)
 
 foreach t: functional_tests