osc-portals4: allow atomic ops on datatypes that are max_fetch_atomic_size bytes in length

Portals4 supports atomic ops on datatypes less than or equal to
max_fetch_atomic_size bytes.  This commit fixes a bug that required
the datatype to be less than max_fetch_atomic_size bytes.

ompi/mca/osc/portals4/osc_portals4_comm.c

@@ -970,7 +970,7 @@ ompi_osc_portals4_compare_and_swap(void *origin_addr,
     ret = ompi_datatype_type_size(dt, &length);
     if (OMPI_SUCCESS != ret) return ret;
 
-    assert(length < module->fetch_atomic_max);
+    assert(length <= module->fetch_atomic_max);
 
     result_md_offset = (ptl_size_t) result_addr;
     origin_md_offset = (ptl_size_t) origin_addr;
@@ -1033,7 +1033,7 @@ ompi_osc_portals4_fetch_and_op(void *origin_addr,
     ret = ompi_datatype_type_size(dt, &length);
     if (OMPI_SUCCESS != ret) return ret;
 
-    assert(length < module->fetch_atomic_max);
+    assert(length <= module->fetch_atomic_max);
 
     (void)opal_atomic_add_64(&module->opcount, 1);