Fix a bug in signature self tests in the FIPS module
Fix a bug in signature self tests in the FIPS module

When calling EVP_PKEY_sign(), the size of the signature buffer must
be passed in *siglen.

Reviewed-by: Tomas Mraz <2bc6038c3dfca09b2da23c8b6da8ba884dc2dcc2@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/16789)

openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl