NO-JIRA: Reduce "No EFP Partition" log message from warning to info.

It is normal for there to be no EFP partition if a broker is being started for
the first time with a clean data directory.

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1619580 13f79535-47bb-0310-9956-ffa450edef68