hob/hoblistmodel: check if vals of packages/recipes names are not None

[YOCTO #5053]

(Corresponds to BitBake master rev: ba9fe77e37be31e8246431578902e871dd94515e)

Signed-off-by: Cristiana Voicu <cristiana.voicu@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>