PATCH: duplicate reference trips up rmap

[FGasper]

use strict;
use warnings;

use Data::Rmap;

my $href = [];

my $struct = {
    foo => $href,
    bar => $href,
};

rmap_all { $_ = 123 if 'ARRAY' eq ref } $struct;

use Data::Dumper;
print Dumper $struct;

The above should convert both $struct values to 123, but it only does one of them. This appears to be because the “seen” hash is populated before the coderef rather than after it.