Use lchown() instead of chown() for self-created files

Use lchown() instead of chown() for self-created files

There is no need to allow symlink dereferencing in these cases where a
file (including directories and sockets) are created by the same
process, so use the safer lchown() variant to avoid leaving potential
windows for something external to replace the file before the chown()
call. The particular locations used here should not have write
permissions enabled for processes with less privileges, so this may not
be needed, but anyway, it is better to make these more restrictive
should there be cases where directory permissions are not as expected
for a good deployment.

Signed-off-by: Jouni Malinen <j@w1.fi>