[FIX] mrp: quick create bom on new mo

Before this commit, an error was raised when you tried to create a
new bill of material on a new manufacturing order.
In fact, the name_create RPC returned 'false' and slow_create()
wasn't executed.

By adding _rec_name (as in 10.0) on the corresponding model, the RPC
call will raise an error that will be caught by quick_create and
forces slow_create().

Closes #9761

addons/mrp/mrp.py

@@ -148,6 +148,7 @@ class mrp_bom(osv.osv):
     _name = 'mrp.bom'
     _description = 'Bill of Material'
     _inherit = ['mail.thread']
+    _rec_name = 'product_tmpl_id'
 
     _columns = {
         'code': fields.char('Reference', size=16),