drm/amdgpu: remove amdgpu_fence_ref/unref

Just move the remaining users to fence_put/get.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c
index 2e946b2..dcf4a8a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c
@@ -54,7 +54,8 @@
 		goto err;
 	}
 
-	fence = amdgpu_fence_ref(job->ibs[job->num_ibs - 1].fence);
+	fence = job->ibs[job->num_ibs - 1].fence;
+	fence_get(&fence->base);
 
 err:
 	if (job->free_job)