ob1: better handling of case when no btls found

that are usable.

Related to #11412

Signed-off-by: Howard Pritchard <howardp@lanl.gov>

Author: hppritcha

ompi/mca/pml/ob1/pml_ob1.c

@@ -400,6 +400,10 @@ int mca_pml_ob1_add_procs(ompi_proc_t** procs, size_t nprocs)
         return rc;
     }
 
+    if (NULL == mca_bml.bml_add_procs) {
+        return OMPI_ERR_UNREACH;
+    }
+
     rc = mca_bml.bml_add_procs (nprocs, procs, &reachable);
     OBJ_DESTRUCT(&reachable);
     if (OMPI_SUCCESS != rc) {

ompi/mca/pml/ob1/pml_ob1_component.c

@@ -326,8 +326,10 @@ int mca_pml_ob1_component_fini(void)
     int rc;
 
     /* Shutdown BML */
-    if(OMPI_SUCCESS != (rc = mca_bml.bml_finalize()))
-        return rc;
+    if (NULL != mca_bml.bml_finalize) {
+        if(OMPI_SUCCESS != (rc = mca_bml.bml_finalize()))
+            return rc;
+    }
 
     if(!mca_pml_ob1.enabled) {
         if( NULL != mca_pml_ob1.allocator ) {