[LV] Remove a change that was added in D106164.

This change wasn't strictly necessary for D106164 and could be removed.
This patch addresses the post-commit comments from @fhahn on D106164, and
also changes sve-widen-gep.ll to use the same IR test as shown in
pointer-induction.ll.

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D106878