libcutils: turn on -Werror

- Deal with some -Wunused / -Wunused-variable issues

Change-Id: I28c23fb213382a392ec30935749fb359e072d664
diff --git a/libcutils/sockets.c b/libcutils/sockets.c
index b5a1b3d..15ede2b 100644
--- a/libcutils/sockets.c
+++ b/libcutils/sockets.c
@@ -14,15 +14,18 @@
  * limitations under the License.
  */
 
-#include <cutils/log.h>
 #include <cutils/sockets.h>
+#include <log/log.h>
 
 #ifdef HAVE_ANDROID_OS
 /* For the socket trust (credentials) check */
 #include <private/android_filesystem_config.h>
+#define __android_unused
+#else
+#define __android_unused __attribute__((__unused__))
 #endif
 
-bool socket_peer_is_trusted(int fd)
+bool socket_peer_is_trusted(int fd __android_unused)
 {
 #ifdef HAVE_ANDROID_OS
     struct ucred cr;