### Please describe the problem.
I tried to use `git-annex-fsck --all --from remote` to check files on a special remote, but git-annex did a scan of the local repo instead. If I don't use the `--all` flag, it correctly checks the files on the remote (but just the files in the current checked out branch).

### What steps will reproduce the problem?
    mkdir repo
    mkdir special
    cd repo
    git init
    git annex init
    git annex initremote special type=directory directory=../special encryption=none
    touch testfile
    git annex add testfile
    git annex copy testfile --to special
    chmod -R +w ../special/*
    rm -r ../special/*
    git annex fsck --all --from special   # should check special remote but checks local repo instead
    git diff git-annex^ git-annex         # activity log shows that it checked special remote
    git annex fsck --from special         # correctly checks special remote, identifies missing file


### What version of git-annex are you using? On what operating system?
6.20161012 on Ubuntu 16.10

### Have you had any luck using git-annex before?
Yes, it's been very helpful for managing large files between laptops, desktops, external storage, and remote storage.

> Thanks for an excellent test case and a clear bug report. I've fixed this
> bug. [[done]] --[[Joey]]
