Cleanup storagemanager compile warnings

messageFormat.h:68:20: warning: ‘storagemanager::socket_name’ defined but not used [-Wunused-variable]

 static const char *socket_name = "\0storagemanager";

SessionManager.cpp:267:36: warning: variable ‘len’ set but not used [-Wunused-but-set-variable]

                     int peakLength,len;