fixed more generic bug of darshan_finalize() causing a segfault if

darshan_initialize() is not executed first


git-svn-id: https://svn.mcs.anl.gov/repos/darshan/trunk@109 3b7491f3-a168-0410-bf4b-c445ed680a29

lib/darshan-mpi-io.c

@@ -204,6 +204,7 @@ void darshan_shutdown(int timing_flag)
     if(!darshan_global_job)
     {
         CP_UNLOCK();
+        return;
     }
     /* disable further tracing while hanging onto the data so that we can
      * write it out