Use TempFile in the implementation of LockFileManager.

This move some of the complexity over to the lower level TempFile.

It also makes it a bit more explicit where errors are ignored since we
now have a call to consumeError.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318550 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed