[llvm] [LLVM][AArch64] Fix invalid use of AArch64ISD::UZP2 in performConcatVectorsCombine. (PR #104774)

[Graham Hunter via llvm-commits]

https://github.com/huntergr-arm approved this pull request.

Nit: would be nice to have a bit more explanation about the fix in the commit message wrt. the differing VT types, but otherwise LGTM.

https://github.com/llvm/llvm-project/pull/104774