[utils] Use print_function in the code coverage prep script, NFC.
[utils] Use print_function in the code coverage prep script, NFC.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@285248 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 1182ed1523ba7eb8bc341d917638ae40187862da)

apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm