fix tempest-lib setup

The setup should have been with setup_dev_lib, which looks up the path
from GITDIR. This should let tempest-lib src jobs function.

Change-Id: Ia160708c089adce469d878030196b6fed8acc92d
diff --git a/lib/tempest b/lib/tempest
index d3fb9fb..6bcfaec 100644
--- a/lib/tempest
+++ b/lib/tempest
@@ -450,7 +450,7 @@
 function install_tempest_lib {
     if use_library_from_git "tempest-lib"; then
         git_clone_by_name "tempest-lib"
-        setup_develop "tempest-lib"
+        setup_dev_lib "tempest-lib"
     fi
 }