This deduplicates the code between QFileSystemEngine and QLockFile.
Change-Id: I1eba2b016de74620bfc8fffd14cd005d5fd9beaa
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@qt.io>
... instead of having (duplicated) code in the configures to create it.
Change-Id: Ia86b44021a024a969f5a49b7fb18d3d414869f93
Reviewed-by: Lars Knoll <lars.knoll@qt.io>