crypto/store/ossl_result.c: Better filtering of errors

crypto/store/ossl_result.c: Better filtering of errors

The diverse variants of try_XXX() were filtering errors independently
of each other.  It's better done in ossl_store_handle_load_result()
itself, where we have control over the overall success and failure of
the attempts.

Fixes #14973

Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/15008)