simplify clatd permission dropping logic

There's no danger here, because we drop privileges
before we start processing packets.

This should also make clatd fully functional on 4.9-q
kernels that still have the Paranoid Android patchset
(by creating all sockets prior to dropping netd's
uid and capabilities).

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I14cab836907be8bbedc0812cec277808e9f3f91f
3 files changed