Fix more issues the dashboards turned up.

Possible unitialized variable warning.
Combine the H5 and XML path tests so that -j N won't run them
simultaneously and sometimes delete each others files.

Change-Id: I0e33394c4a2f8dbe8943e48165da3ca6f6e0ff0a
Merge topic 'newest-xdmf' into master

5a231472 Fix more issues the dashboards turned up.