src/signature: no need to pass uninitalized certs arg to CMS_verify
src/signature: no need to pass uninitalized certs arg to CMS_verify

This may contain additional certs to be used for verification, but is
useless if certs are not initialized.

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

jluebbe/rauc,rauc/rauc,jluebbe/rauc,ejoerns/rauc,rauc/rauc,ejoerns/rauc,ejoerns/rauc,jluebbe/rauc,rauc/rauc