The split_and_strip_files funciton was hard to follow and its usage of prefixes
to strings was unusual. This rewrites it to use a list of hardlinks, symlinks and
elffiles where each list is iterated over at the correct point.
This means we can avoid creating dandling symlinks for example so we can simply
delete the cleanup code for this.
The isfile() check is also removed which gives a significant improvement in speed.
Its uneeded since os.walk will have already checked things in files are files.
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
