This was added to allow detection of duplicate files being installed by sstate.
There is a much simpler way, just check if the file already exists. This
effectively uses the kernel VFS as the cache which is much more efficient.
This resolves a significant performance bottleneck (lock contention on a
single file) when running builds that are just being generated from sstate
cache files.
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
