Previously, if a write or sync error occurred, we would not have called
Close(). This commit refactors ReplaceFile() so that we are sure to call
Close(), and also attempts to delete the temporary file if errors occur.
This reverts commit f4afdecef8, reversing
changes made to e633a1604f.
This also fixes a bug where Kubemark was still using the core api scheme
to manipulate the Kubelet's types, which was the cause of the initial
revert.