wined3d: Use the format info to determine the A8_UNORM output swizzle in find_ps_compile_args().

dlls/wined3d/shader.c

@@ -4159,15 +4159,12 @@ void find_ps_compile_args(const struct wined3d_state *state, const struct wined3
     args->render_offscreen = shader->reg_maps.vpos && gl_info->supported[ARB_FRAGMENT_COORD_CONVENTIONS]
             ? context->render_offscreen : 0;
 
-    if (!gl_info->supported[WINED3D_GL_LEGACY_CONTEXT])
-    {
     for (i = 0; i < ARRAY_SIZE(state->fb->render_targets); ++i)
     {
         struct wined3d_rendertarget_view *rtv = state->fb->render_targets[i];
-            if (rtv && rtv->format->id == WINED3DFMT_A8_UNORM)
+        if (rtv && rtv->format->id == WINED3DFMT_A8_UNORM && !is_identity_fixup(rtv->format->color_fixup))
             args->rt_alpha_swizzle |= 1u << i;
     }
-    }
 }
 
 static HRESULT pixel_shader_init(struct wined3d_shader *shader, struct wined3d_device *device,