d3d12: Adjust polygon offset units

src/gallium/drivers/d3d12/d3d12_pipeline_state.cpp

@@ -249,7 +249,7 @@ create_gfx_pipeline_state(struct d3d12_context *ctx)
       pso_desc.RasterizerState.CullMode = D3D12_CULL_MODE_NONE;
 
    if (depth_bias(state->rast, reduced_prim)) {
-      pso_desc.RasterizerState.DepthBias = state->rast->base.offset_units;
+      pso_desc.RasterizerState.DepthBias = state->rast->base.offset_units * 2;
       pso_desc.RasterizerState.DepthBiasClamp = state->rast->base.offset_clamp;
       pso_desc.RasterizerState.SlopeScaledDepthBias = state->rast->base.offset_scale;
    }