Minor nit: use the real filename. opal_show_help() will ultimately

find the file even if we don't specify the ".txt" extension here, but
we might as well do it Right in the first place.

This commit was SVN r19867.

ompi/mca/bml/r2/bml_r2.c

@@ -403,7 +403,7 @@ static int mca_bml_r2_add_procs( size_t nprocs,
 
     if (mca_bml_r2.show_unreach_errors && 
         OMPI_ERR_UNREACH == ret) {
-        orte_show_help("help-mca-bml-r2",
+        orte_show_help("help-mca-bml-r2.txt",
                        "unreachable proc",
                        true, 
                        ORTE_NAME_PRINT(&(ompi_proc_local_proc->proc_name)),