[PATCH] drm/amdgpu: Return more error codes in amdgpu_connector_set_property()

[Markus Elfring]

> The "if(!encoder)" branch return the same value 0 of the success
> branch, maybe return -EINVAL is more better.

I suggest to improve the commit message.

* Would you like to adjust the patch subject?

* How do you think about to add the tag “Fixes”
  because of adjustments for the exception handling?

Regards,
Markus