Fix a few erroneous double frees in quic-hq-interop

Uncovered during testing for openssl/project#1130

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Saša Nedvědický <sashan@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/27004)

test/quic-openssl-docker/hq-interop/quic-hq-interop.c

@@ -825,6 +825,9 @@ end:
     SSL_CTX_free(*ctx);
     SSL_free(*ssl);
     BIO_ADDR_free(peer_addr);
+    *ctx = NULL;
+    *ssl = NULL;
+    peer_addr = NULL;
     return 0;
 }