Bug#839024: man page: document --deflate

[Mathieu Malaterre]

Package: binwarlk
Version: 2.1.1-9

For some reason some options are not documented in the man page which
is rather confusing. Eg `--deflate` is not present in the man page,
but is:

$ binwalk -h | grep defl
    -X, --deflate                Scan for raw deflate compression streams

Thanks