ALLJOYN-1602: SessionJoined was returning the wrong joiner when only a single daemon was involved

Change-Id: I38fb3a06d7e5e6d7e886daf0b7e898947c812f27
ALLJOYN-1662 Resolve Klocwork issue 1314

Change-Id: I9f5101eff36dd88e8b75d235bb5750f0ae6565e9