Fix the return value for SSL_get0_chain_certs()

This function was always returning 0. It should return 1 on success.

Fixes #9374
Reviewed-by: NKurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/9395)

(cherry picked from commit 7bc82358ae930cfbd353602bc1fd25bfad107350)

ssl/s3_lib.c

@@ -3567,6 +3567,7 @@ long ssl3_ctrl(SSL *s, int cmd, long larg, void *parg)
 
     case SSL_CTRL_GET_CHAIN_CERTS:
         *(STACK_OF(X509) **)parg = s->cert->key->chain;
+        ret = 1;
         break;
 
     case SSL_CTRL_SELECT_CURRENT_CERT: