Cleanup old-style-cast warnings

Change-Id: I6e17fd993557cbf78ade787f112794358aee39c8
diff --git a/libziparchive/Android.mk b/libziparchive/Android.mk
index ba7b74d..3937449 100644
--- a/libziparchive/Android.mk
+++ b/libziparchive/Android.mk
@@ -24,7 +24,8 @@
 LOCAL_STATIC_LIBRARIES := libz
 LOCAL_SHARED_LIBRARIES := libutils
 LOCAL_MODULE:= libziparchive
-LOCAL_CFLAGS := -Werror
+LOCAL_CFLAGS := -Werror -Wall
+LOCAL_CPPFLAGS := -Wold-style-cast
 include $(BUILD_STATIC_LIBRARY)
 
 include $(CLEAR_VARS)