Refactor sktm.watcher.check_patchwork to not need trivial comments

[spbnick]

At the moment the sktm.watcher.check_patchwork function needs a bunch of comments to explain what it loops over (and for some other trivial parts), which indicates the code is a bit obscure. Refactor the function and possibly some other related parts of sktm.watcher to reduce the need for such comments.