core/pkg-generic: reorder variables definitions for legal-info

core/pkg-generic: reorder variables definitions for legal-info

Move the declarations of _ACTUAL_SOURCE and _ACTUAL_SITE earlier, so
that they are close to where _SOURCE and _SITE are handled.

This looks so far like a purely cosmetic change, but makes more sense
with the follow-up patch, where we'll need them earlier in the file.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Arnout Vandecappelle <arnout@mind.be>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
Tested-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>