Hob: fixed a little view issue about package selection page

In package selection page, treeview cell data callback function not cover the 'else' case, so parent item will render the pervious value.

(Bitbake rev: 98694c1dbc276cc151f393db67bfd43442da28ba)

Signed-off-by: Liming An <limingx.l.an@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/ui/crumbs/hobwidget.py

@@ -174,7 +174,8 @@ class HobViewTable (gtk.VBox):
         if binb:
             bin = binb.split(', ')
             cell.set_property('text', bin[0])
-
+        else:
+            cell.set_property('text', "")
         return True
 
     def set_model(self, tree_model):