drm/amdgpu/powerplay/vega10: handle error in getting pptable

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 2020-12-01 08:51:06 -05:00
commit 9805e1adab