[IMP] account_asset_management: Simplify code for opening related entries

We don't need the search having the one2many field and no need also for list
comprehension having mapped operator.

account_asset_management/models/account_asset.py

@@ -443,9 +443,6 @@ class AccountAsset(models.Model):
     @api.multi
     def open_entries(self):
         self.ensure_one()
-        amls = self.env['account.move.line'].search(
-            [('asset_id', '=', self.id)], order='date ASC')
-        am_ids = [l.move_id.id for l in amls]
         # needed for avoiding errors after grouping in assets
         context = dict(self.env.context)
         context.pop('group_by', None)
@@ -457,7 +454,8 @@ class AccountAsset(models.Model):
             'view_id': False,
             'type': 'ir.actions.act_window',
             'context': context,
-            'domain': [('id', 'in', am_ids)],
+            'domain': [
+                ('id', 'in', self.account_move_line_ids.mapped('move_id').ids)]
         }
 
     @api.multi