Bug fix: correct is_stratis_device
Bug fix: correct is_stratis_device

The .filter(|x| is_stratis_device(&x).ok().is_some())
This converts the Result to an Option (resulting in an Option<Option<uuid>>)
and then checks if the outermost option is some, but it's only a
Stratis device if the interior Option is Some

Thanks to Grover for pointing this out.

Signed-off-by: Tony Asleson <1ef2d381aa56d512126ddaacc29e68136e4fdf55@redhat.com>

stratis-storage/stratisd,trgill/stratisd,trgill/stratisd,mulkieran/stratisd,stratis-storage/stratisd,mulkieran/stratisd,stratis-storage/stratisd