handleLChmod() does not properly check that files behind the handlinks exist
before calling os.Chmod(). We've seen base images where this results in
"no such file or directory" error from os.Chmod() when unpacking the image.
To keep the existing logic but fix the problem, this commit simply skips
IsNotExist error.
Signed-off-by: Mikko Ylinen <mikko.ylinen@intel.com>