max_prune_rate in global pruning

[AvrahamRaviv]

It seems that using global pruning isn't working together with max_prune_rate . I suggest adding the second condition in metapruner.py:

imp_argsort = torch.argsort(imp)
if len(_pruning_indices)>0 and self.round_to:
    n_pruned = len(_pruning_indices)
    current_channels = get_channel_fn(module)
    n_pruned = self._round_to(n_pruned, current_channels, self.round_to)
    _pruning_indices = imp_argsort[:n_pruned]
# ----->
if len(_pruning_indices) > 0 and self.max_pruning_ratio < 1:
    n_pruned = len(_pruning_indices)
    while n_pruned / get_channel_fn(module) > self.max_pruning_ratio:
        n_pruned = len(_pruning_indices) - 1
        _pruning_indices = imp_argsort[:n_pruned]
# <-----
pruning_indices.append(_pruning_indices)