crypto/provider_conf.c: Fix possible memory leak

crypto/provider_conf.c: Fix possible memory leak

Assign the return value of ossl_provider_info_add_to_store to added instead of
setting it directly to 1, in order to avoid a memory leak caused by entry not
being freed if ossl_provider_info_add_to_store() fails.

Signed-off-by: JiashengJiang <jiasheng@purdue.edu>
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/27472)