Switch this code to a more idiomatic double using namespace directive.

Switch this code to a more idiomatic double using namespace directive.

Fix a truly odd namespace qualifier that was flat out wrong in the
process. The fully qualified namespace would have been
llvm::sys::TimeValue, llvm::TimeValue makes no sense.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171292 91177308-0d34-0410-b5e6-96231b3b80d8