Remove the unused function - amdgpu_vm_pt_is_root_clean
and remove the impossible condition
v1: entries == 0 is not possible any more,
so this condition could probably be removed (Felix)
Signed-off-by: Jesse Zhang <jesse.zhang@amd.com>
Suggested-by:Felix Kuehling <felix.kuehling@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>