[llvm] [mlir:x86vector:transform] Fix bazel build (again) after #168074. (PR #169316)

[Ingo Müller via llvm-commits]

ingomueller-net wrote:

I do not understand why the build passed locally but failed in CI.

Please wait with merging until CI passes.

https://github.com/llvm/llvm-project/pull/169316