Fix a travis failure

Travis was indicating a bogus uninit var warning. This fixes it.

Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

ssl/statem/statem_clnt.c

@@ -1110,6 +1110,7 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
             goto f_err;
         }
     } else {
+        PACKET_null_init(&session_id);
         session_id_len = 0;
     }