[llvm] [SLP][NFC] Remove useless code of deleting ExtractElementInst (PR #106697)

[via llvm-commits]

tcwzxx wrote:

https://github.com/llvm/llvm-project/blob/68f0d20a9b507383a7577144bbd4811abe787e42/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp#L12178-L12196

> // If the only one use is vectorized - can delete the extractelement 
 // itself. 

When the only use is vectorized, `removeInstructionsAndOperands` will drop the scalars and the operator of those scalars (where `EI` is the operator of those scalars).


https://github.com/llvm/llvm-project/pull/106697