ofp-actions: Avoid buffer overread in BUNDLE action decoding.

Reported-at: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=9052
Signed-off-by: Ben Pfaff <blp@ovn.org>
Acked-by: Justin Pettit <jpettit@ovn.org>
format_SET_MPLS_TC(const struct ofpact_mpls_tc *a, struct ds *s)
{
    ds_put_format(s, "%sset_mpls_ttl(%s%"PRIu8"%s)%s",
                  colors.paren, colors.end, a->tc,
                  colors.paren, colors.end);
}

format_SET_MPLS_TC(const struct ofpact_mpls_tc *a, struct ds *s)
{
    ds_put_format(s, "%sset_mpls_ttl(%s%"PRIu8"%s)%s",
                  colors.paren, colors.end, a->tc,
                  colors.paren, colors.end);
}
