CRM-14590 - Custom fields for a particular role are not being saved in backend registrations.

Also cleaned up a spelling error.
EG. "if (($this->_lineItem || !isset($params['proceSetId']))"  proceSetId should be priceSetId.

Also moved getting $this->_params['participant_role_id'] out of the if statement since it was used elsewhere. This gets rid of the notice on line 1152.