logcat: turn on -Werror

- Deal with some -Wunused issues

Change-Id: Ic4ab9a49f13e156a73d40266e413dee3e6396178
diff --git a/logcat/Android.mk b/logcat/Android.mk
index b5e27eb..f46a4de 100644
--- a/logcat/Android.mk
+++ b/logcat/Android.mk
@@ -7,7 +7,9 @@
 
 LOCAL_SHARED_LIBRARIES := liblog
 
-LOCAL_MODULE:= logcat
+LOCAL_MODULE := logcat
+
+LOCAL_CFLAGS := -Werror
 
 include $(BUILD_EXECUTABLE)