Navigation: getAjaxFormData: Simplify code.
Navigation: getAjaxFormData: Simplify code.

Idea from: https://github.com/jquery/jquery-mobile/commit/0d4e839#commitcomment-2811047

arschmitz/jquery-mobile,hinaloe/jqm-demo-ja,arschmitz/uglymongrel-jquery-mobile,hinaloe/jqm-demo-ja,arschmitz/uglymongrel-jquery-mobile,startxfr/jquery-mobile,startxfr/jquery-mobile,arschmitz/jquery-mobile,arschmitz/jquery-mobile,hinaloe/jqm-demo-ja,startxfr/jquery-mobile,arschmitz/uglymongrel-jquery-mobile