pua_reginfo: fix memory leak when usrloc is DB_ONLY
As release_urecord() clearly says:
/*!
* \brief Release urecord previously obtained through get_urecord
* \warning Failing to calls this function after get_urecord will
* result in a memory leak when the DB_ONLY mode is used. When
* the records is later deleted, e.g. with delete_urecord, then
* its not necessary, as this function already releases the record.
* \param _r released record
*/