content: support filters on local.store#Walk()

While Walk() has been taking filter strings, it was not using the parameter.
This change actually makes the filtering work.

Signed-off-by: Kazuyoshi Kato <katokazu@amazon.com>

metadata/content.go

@@ -181,7 +181,7 @@ func (cs *contentStore) Walk(ctx context.Context, fn content.WalkFunc, fs ...str
 			if err := readInfo(&info, bkt.Bucket(k)); err != nil {
 				return err
 			}
-			if filter.Match(adaptContentInfo(info)) {
+			if filter.Match(content.AdaptInfo(info)) {
 				infos = append(infos, info)
 			}
 			return nil