[FIX] hr_expense: Submit to manager from an other company

Steps to reproduce the bug:

- Let's consider a user U linked to employee E
- U is allowed to access to company C1 and C2
- E is in the department D in company C1
- Log as U in C2
- Create an expense XP
- Submit XP to your manager
- Click on button 'Save'

Bug:

An access rights error was raised because D was not readable in C1.

opw:2092710

closes odoo/odoo#39928

Signed-off-by: Simon Goffin (sig) <sig@openerp.com>