Fix incorrect behavior noted by Lisandro Dalcini: when MPI_COMM_SELF is

passed to MPI_COMM_FREE, it invoked the error handler on
MPI_COMM_WORLD, not on MPI_COMM_FREE.  This commit changes the
behavior: if MPI_COMM_SELF is passed to MPI_COMM_FREE, we invoke the
error handler on MPI_COMM_SELF (not MPI_COMM_WORLD).  Fixes trac:1109.

This commit was SVN r15682.

The following Trac tickets were found above:
  Ticket 1109 --> https://svn.open-mpi.org/trac/ompi/ticket/1109

ompi/mpi/c/comm_free.c

@@ -41,9 +41,12 @@ int MPI_Comm_free(MPI_Comm *comm)
         OMPI_ERR_INIT_FINALIZE(FUNC_NAME);
         
         if ( NULL == *comm  || MPI_COMM_WORLD == *comm ||
-             MPI_COMM_SELF == *comm  || ompi_comm_invalid (*comm)) {
+             ompi_comm_invalid (*comm)) {
             return OMPI_ERRHANDLER_INVOKE(MPI_COMM_WORLD, MPI_ERR_COMM, 
                                           FUNC_NAME);
+        } else if (MPI_COMM_SELF == *comm) {
+            return OMPI_ERRHANDLER_INVOKE(MPI_COMM_SELF, MPI_ERR_COMM, 
+                                          FUNC_NAME);
         }
     }