[NVPTX] Remove dead code.

Found by the Clang static analyzer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218874 91177308-0d34-0410-b5e6-96231b3b80d8
Remove duplicate function names from comments. NFC.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218875 91177308-0d34-0410-b5e6-96231b3b80d8
Use the local variable that other clauses around here are already using.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218876 91177308-0d34-0410-b5e6-96231b3b80d8