vkr: update vn_info_extension_get and fix callers
The goal is to minimize diffs when we add extensions in the future.
Headers are generated by https://gitlab.freedesktop.org/olv/venus-protocol/-/merge_requests/38.
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The goal is to minimize diffs when we add extensions in the future.
Headers are generated by https://gitlab.freedesktop.org/olv/venus-protocol/-/merge_requests/38.