pull-local: Write detached metadata into the correct repository

We want to write to the dest repo, not src.

Noticed while reviewing this code for some other bug.

https://bugzilla.gnome.org/show_bug.cgi?id=733579

src/ostree/ot-builtin-pull-local.c

@@ -91,7 +91,7 @@ import_one_object (OtLocalCloneData *data,
 
           if (detached_meta)
             {
-              if (!ostree_repo_write_commit_detached_metadata (data->src_repo,
+              if (!ostree_repo_write_commit_detached_metadata (data->dest_repo,
                                                                checksum, detached_meta,
                                                                cancellable, error))
                 goto out;