fix newer isort behavior wherein it expect an input file to process

The behavior in newer version of isort has changed, wherein it expects input files that needs to be processed.

$ isort --check-only --diff

...snipped...

Nothing to do: no files or paths have have been passed in!

Try one of the following:

    `isort .` - sort all Python files, starting from the current directory, recursively.
    `isort . --interactive` - Do the same, but ask before making any changes.
    `isort . --check --diff` - Check to see if imports are correctly sorted within this project.
    `isort --help` - In-depth information about isort's available command-line options.

Visit https://timothycrosley.github.io/isort/ for complete information about how to use isort.

Error: arguments passed in without any paths or content.

Signed-off-by: Ritesh Raj Sarraf ritesh.sarraf@collabora.com