[FIX] analytic: methods used in default attribute should return a RecordSet

If a method used as a default returns an id instead of a RecordSet,
it could fail in 'convert_to_write' (Many2One field) because it will try
to return "value.id". If "value" is an integer, it fails.

Also changed the method to a lambda expression and removed the
'_default_user' method because it's not used anywhere.

addons/analytic/models/analytic.py

@@ -41,14 +41,6 @@ class account_analytic_account(models.Model):
             account.credit = data_credit.get(account.id, 0.0)
             account.balance = account.credit - account.debit
 
-    @api.model
-    def _default_company(self):
-        return self.env.user.company_id.id
-
-    @api.model
-    def _default_user(self):
-        return self.env.user.id
-
     name = fields.Char(string='Analytic Account', index=True, required=True, track_visibility='onchange')
     code = fields.Char(string='Reference', index=True, track_visibility='onchange')
     account_type = fields.Selection([
@@ -58,7 +50,7 @@ class account_analytic_account(models.Model):
     tag_ids = fields.Many2many('account.analytic.tag', 'account_analytic_account_tag_rel', 'account_id', 'tag_id', string='Tags', copy=True)
     line_ids = fields.One2many('account.analytic.line', 'account_id', string="Analytic Lines")
 
-    company_id = fields.Many2one('res.company', string='Company', required=True, default=_default_company)
+    company_id = fields.Many2one('res.company', string='Company', required=True, default=lambda self: self.env.user.company_id)
     partner_id = fields.Many2one('res.partner', string='Customer')
 
     balance = fields.Monetary(compute='_compute_debit_credit_balance', string='Balance')