Eo: Make eo_parent_get accept const.

SVN revision: 70864

legacy/eobj/lib/Eo.h

@@ -530,7 +530,7 @@ EAPI Eo *eo_add(const Eo_Class *klass, Eo *parent);
  * @param obj the object to get the parent of.
  * @return a pointer to the parent object.
  */
-EAPI Eo *eo_parent_get(Eo *obj);
+EAPI Eo *eo_parent_get(const Eo *obj);
 
 /**
  * @brief Get a pointer to the data of an object for a specific class.

legacy/eobj/lib/eo.c

@@ -1097,7 +1097,7 @@ eo_del(Eo *obj)
 }
 
 EAPI Eo *
-eo_parent_get(Eo *obj)
+eo_parent_get(const Eo *obj)
 {
    EO_MAGIC_RETURN_VAL(obj, EO_EINA_MAGIC, NULL);