basesmuma: modify the minimum size for the large fan-in fan-out allreduce

algorithm

Per suggestion from Manju make sure there isn't a gap in the size ranges
for the available algorithms.

cmr=v1.8.2:ticket=trac:4437:reviewer=ompi-rm1.8

This commit was SVN r31728.

The following Trac tickets were found above:
  Ticket 4437 --> https://svn.open-mpi.org/trac/ompi/ticket/4437

ompi/mca/bcol/basesmuma/bcol_basesmuma_allreduce.c

@@ -55,7 +55,7 @@ int bcol_basesmuma_allreduce_init(mca_bcol_base_module_t *super)
                                  bcol_basesmuma_allreduce_intra_fanin_fanout,
                                  bcol_basesmuma_allreduce_intra_fanin_fanout_progress);
 
-    inv_attribs.bcol_msg_min = 10000000;
+    inv_attribs.bcol_msg_min = 20000;
     inv_attribs.bcol_msg_max = 10485760; /* range 4 */
     mca_bcol_base_set_attributes(super, &comm_attribs, &inv_attribs,
                                  bcol_basesmuma_allreduce_intra_fanin_fanout,