classes: bundle: do not check for RAUC_KEY_FILE during parsing
classes: bundle: do not check for RAUC_KEY_FILE during parsing

If the check is performed by python __anonymous() function, the test
will always be executed right after parsing the recipe.
The result of this is that when not having RAUC_KEY_FILE/RAUC_CERT_FILE
set, every bitbake invocation will fail, no matter which recipe we gonna
build.

A this is a very bad behavior, we move the check to where it is really
needed: At the beginning of the do_bundle() task, right before invoking
RAUC to actually build the bundle.

This way we will abort with a helpful message during do_bundle() task
(when building a RAUC bundle from an non-prepared environment), while
still being able to build all other non-RAUC-related packages without
errors.

Signed-off-by: Enrico Joerns <a2e5f936c390f36494e46e71bcfbe365bb1e8c49@pengutronix.de>

rauc/meta-rauc,rauc/meta-rauc,rauc/meta-rauc,rauc/meta-rauc