vendorsetup: Handle new jenkins build parameters

* https://github.com/CyanogenMod/hudson/commit/21c0d29e0038cfb61d8e1fd404fb162fe385a093

 broke the previous way of adding lunch targets, as it was
    adding a 'bacon' target instead of the full lunch-able target (cm_bacon-$variant).
* use printf and format the combo during the parsing

Change-Id: I0d2c4716bf17cb1a85333662f941d454d0b74e6a
Signed-off-by: Brandon McAnsh <brandon.mcansh@gmail.com>