[FIX] product: The pricelist variable must be a recordset, not a list

Steps to reproduce the bug:

-On an empty database, install the sale module
-Activate product variants : Sales > Settings > Check Products can have several attributes, defining variants (Example: size, color,...)
-Activate advanced pricelists : Sales > Settings > Check Advanced pricing based on formulas (discounts, margins, rounding)
-Activate the developer mode
-Go to the product.templates list : Sales > Products
-Go to the debug menu > Edit TreeView and add the price field in the view
-Search for a pricelist : Type the name of an existing pricelist, then go to the pricelists proposal,
open the list of proposed pricelists, and select the pricelist

Bug:

A traceback was raised.

opw:762663

addons/product/models/product_template.py

@@ -164,7 +164,9 @@ class ProductTemplate(models.Model):
 
             # Support context pricelists specified as display_name or ID for compatibility
             if isinstance(pricelist_id_or_name, basestring):
-                pricelist = self.env['product.pricelist'].name_search(pricelist_id_or_name, operator='=', limit=1)
+                pricelist_data = self.env['product.pricelist'].name_search(pricelist_id_or_name, operator='=', limit=1)
+                if pricelist_data:
+                    pricelist = self.env['product.pricelist'].browse(pricelist_data[0][0])
             elif isinstance(pricelist_id_or_name, (int, long)):
                 pricelist = self.env['product.pricelist'].browse(pricelist_id_or_name)