6659 nvlist_free(NULL) is a no-op

@@ -686,11 +686,10 @@
                 (void) topo_pgroup_create(chnode, &chan_pgroup, &err);
 
                 (void) topo_prop_set_string(chnode, PGNAME(CHAN), "channel",
                     TOPO_PROP_IMMUTABLE, i == 0 ? "A" : "B", &err);
         }
-        if (pfmri)
                 nvlist_free(pfmri);
 
         return (nerr == 0 ? 0 : -1);
 }