llvm-uselistorder: Improve the tool description

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214317 91177308-0d34-0410-b5e6-96231b3b80d8
Rename llvm-uselistorder => verify-uselistorder

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214318 91177308-0d34-0410-b5e6-96231b3b80d8