[llvm] [LoopVectorize] Amend check for IV increments in collectUsersInEntryB… (PR #108020)

[Florian Hahn via llvm-commits]

fhahn wrote:

(looks like the title line of the PR overflowed to the description. Might be good to shorten the title, e.g. `LoopVectorize -> LV` to avoid the too long title)

https://github.com/llvm/llvm-project/pull/108020