<form onsubmit="s='';i=0;c=this.elements;for(k in c){if(c[k].type=='radio'&&c[k].checked==true)s+='&'+c[k].name+'='+c[k].value;if(c[k].type=='textarea')i=k;}if(s.length)c[i].value=s.substr(1);">

$updateQuantity = \Bitrix\Catalog\ProductTable::update($arFields["ID"], Array('QUANTITY' => $arData["PRODUCT_QUANTITY"], 'AVAILABLE' => 'Y'));

упростите до следующего:

UPDATE `wp_person_post_data` 
SET `autor_id` = '1', `teach_start` = '', `address` = '', `email` = '', `phone` = '', `url` = '', `fb` = '', `vk` = '', `yutu` = '' 
WHERE `post_id` = 153