tools: remove unnecessary typename

This is acceptted by clang and gcc, but MSVC seems to balk at it.  As it is
unneeded, simply drop it.  Fixes MSVC buildbots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200456 91177308-0d34-0410-b5e6-96231b3b80d8
tools: fix Twine abuse

utohexstr provides a temporary string, making it unsafe to use with the Twine
interface which will not copy the string.  Switch to using std::string.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200457 91177308-0d34-0410-b5e6-96231b3b80d8