[NVPTX] Fix function names in ctlz.ll test.  Test-only change.

Looks like a copy/paste mistake, all the functions in ctlz.ll were named
"ctpop".

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292300 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed