[REF][8.0][hr_payroll_account] Get partner_id with a function to inheritable case

Proposal to add a REF - More info here: https://github.com/odoo/odoo/issues/3274
OPW ticket 616565

@mart-e 
Im confused, sorry.
Can you help me to write your comment into line code as this one, please?

What is the section that I need change it?