Add a little more to the docs for mca_base_var_enum_create().

This commit was SVN r29496.

opal/mca/base/mca_base_var_enum.h

@@ -143,9 +143,14 @@ OPAL_DECLSPEC OBJ_CLASS_DECLARATION(mca_base_var_enum_t);
  * @retval opal error code On error
  *
  * This function creates a value enumerator for integer variables. The
- * value array is stored by reference in the enumerator so it should not
+ * value array is stored by reference in the enumerator so it should
- * be allocated on the stack. The returned enumerator should be released with
+ * not be allocated on the stack. The OUT enumerator value will be a
+ * newly OBJ_NEW'ed object that should be released by the caller via
  * OBJ_RELEASE.
+ *
+ * Note that the output enumerator can be OBJ_RELEASE'd after it has
+ * been used in a pvar registration, because variables that use the
+ * enumerator will OBJ_RETAIN it.
  */
 OPAL_DECLSPEC int mca_base_var_enum_create (char *name, mca_base_var_enum_value_t values[],
                                             mca_base_var_enum_t **enumerator);