Correct variables masquerading as strings

* jeepyb/cmd/create_cgitrepos.py: Brown bag fix for variables in
sheep's clothing.

Change-Id: I851e8a09b4ebf35c30c791c4b5d630f710cf36f9
diff --git a/jeepyb/cmd/create_cgitrepos.py b/jeepyb/cmd/create_cgitrepos.py
index 07a9eb9..bda452f 100644
--- a/jeepyb/cmd/create_cgitrepos.py
+++ b/jeepyb/cmd/create_cgitrepos.py
@@ -50,7 +50,7 @@
         gitorgs.setdefault(org, []).append((name, description))
     if SCRATCH_SUBPATH:
         assert SCRATCH_SUBPATH not in gitorgs
-        scratch_path = os.path.join('REPO_PATH', 'SCRATCH_SUBPATH')
+        scratch_path = os.path.join(REPO_PATH, SCRATCH_SUBPATH)
         for org in gitorgs:
             scratch_dir = os.path.join(scratch_path, org)
             if not os.path.isdir(scratch_dir):