venus: Drop incorrectly-used always-true pipeline vars

venus: Drop incorrectly-used always-true pipeline vars

When writing vn_fix_graphics_pipeline_create_info() long ago, I defined
some always-true dummy vars that represented some
VkGraphicsPipelineLibraryFlagsEXT. In the conditions that decide which
state to fixup, I used the dummy vars.

My intent was that this would ease the implementation of
VK_EXT_graphics_pipeline_library, because some of the GPL fixup logic
would already be present.  I was wrong. After I studied GPL more,
I discovered that the conditions were using the dummy vars incorrectly.
The incorrect usage produced no bugs, because the vars are always true.

Delete the dummy vars.

Signed-off-by: Lina Versace <linyaa@google.com>
Reviewed-by: Yiwei Zhang <zzyiwei@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22419>