[Intel-gfx] [PATCH i-g-t 1/3] lib/igt_sysfs: Remove support for finding sysfs path with no device opened

[Chris Wilson]

Quoting Tvrtko Ursulin (2017-11-28 18:09:55)
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> It looks like no callers actually use this so remove it to simplify.

We just added more users to the equivalent for debugfs, and accepting -1
here was simply to have consistency with our debugfs api.

If that makes any difference, principle of least surprise or something.
-Chris