drm/amdgpu/pm: Remove gpu_od if it's an empty directory

gpu_od should be removed if it's an empty directory
Signed-off-by: Ma Jun <Jun.Ma2@amd.com>
Reported-by: Yang Wang <kevinyang.wang@amd.com>
Reviewed-by: Yang Wang <kevinyang.wang@amd.com>
Suggested-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/pm/amdgpu_pm.c

@@ -4338,6 +4338,13 @@ static int amdgpu_od_set_init(struct amdgpu_device *adev)
 		}
 	}
 
+	/*
+	 * If gpu_od is the only member in the list, that means gpu_od is an
+	 * empty directory, so remove it.
+	 */
+	if (list_is_singular(&adev->pm.od_kobj_list))
+		goto err_out;
+
 	return 0;
 
 err_out: