We have a dedicated error API for hints. Use it instead of embedding
the hint in the error message, as recommanded in the "qapi/error.h"
header file.
Since spapr_caps_apply() passes &error_fatal, all functions must
also call the ERRP_AUTO_PROPAGATE() macro for error_append_hint()
to be functional.
While here, add some missing braces around one line statements that
are part of the patch context. Also have cap_fwnmi_apply(), which
already uses error_append_hint() to call ERRP_AUTO_PROPAGATE() as
well.
Signed-off-by: Greg Kurz<groug@kaod.org>