field_attach_validate not called for log entitis

This has caused some errors with GEOS enabled:

Exception: ParseException: Expected word but encountered end of stream in GEOSWKTReader->read() (line 38 of /var/www/html/profiles/farm/modules/contrib/geophp/geoPHP/lib/adapters/WKT.class.php)

From @m.stenta comment: "there is an interesting comment in geofield_field_presave()... i wonder if related:"

    /**
     * Edge case. Currently, Drupal will set a field value to the default value if the current value
     * is empty, even if it's set by the user. This bypasses our validation, and currently non-valid WKB
     * data in geom causes catastrophic failures in entity_load. To compensate, we add the default value
     * in early. When the core issue is fixed, we should drop this code.
     *
     * Geofield Issue: http://drupal.org/node/1886852
     * Core Issue: http://drupal.org/node/1253820
     */

It seems that also is saving empty values when it should not

This should be the correct way, not sure if will be affected by geophp but it's a more correct start