fix incorrect path

lxr.conf

@@ -180,7 +180,7 @@ sourceroot: mozillasvn-all /data/mxr-data/mozillasvn-all/svn.mozilla.org
 sourceprefix: mozillasvn-all svn.mozilla.org
 sourceroot: mozillausers-central /data/mxr-data/mozillausers-central/users
 sourceprefix: mozillausers-central mozillausers
-sourceroot: mozmill-tests /data/mxr-data/mozmill-tests
+sourceroot: mozmill-tests /data/mxr-data/mozmill-tests/mozmill-tests
 sourceprefix: mozmill-tests mozmill-tests
 sourceroot: nspr /data/mxr-data/nspr/mozilla
 sourceprefix: nspr nspr