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
diff --git a/clatd.h b/clatd.h
index 34fa885..75ffea3 100644
--- a/clatd.h
+++ b/clatd.h
@@ -40,7 +40,7 @@
 
 void configure_tun_ip(const struct tun_data *tunnel, const char *v4_addr, int mtu);
 void set_capability(uint64_t target_cap);
-void drop_root_but_keep_caps();
+void drop_root_and_caps();
 void open_sockets(struct tun_data *tunnel, uint32_t mark);
 int ipv6_address_changed(const char *interface);
 int configure_clat_ipv6_address(const struct tun_data *tunnel, const char *interface,