LiveRangeEdit: Simplify code; NFC

Simplify the code slightly: Instead of creating empty subranges in one
case and immediately removing them, do not create them in the first
place.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@322226 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed