Fix VectorUtils include guard name (NFC)

VectorUtils was moved to Analysis from Transforms/Utils, but some comments and
the include guard name still reflect its old location.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293684 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed