Add NULL check

Reviewed-by: Saša Nedvědický <sashan@openssl.org>
Reviewed-by: Paul Yang <paulyang.inf@gmail.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <ppzgs1@gmail.com>
Reviewed-by: Neil Horman <nhorman@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/28221)

crypto/x509/v3_attrdesc.c

@@ -67,6 +67,8 @@ static int i2r_HASH(X509V3_EXT_METHOD *method,
     }
     if (BIO_printf(out, "%*sHash Value: ", indent, "") <= 0)
         return 0;
+    if (hash->hashValue == NULL)
+        return 0;
     return ossl_bio_print_hex(out, hash->hashValue->data, hash->hashValue->length);
 }