drm/amdgpu/powerplay/tonga: return an error if copying to smc fails

Rather than just silently dropping it.  Also fixes a set but
unused variable warning.

Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Alex Deucher 2020-11-30 18:06:49 -05:00
commit 54915feea3