Use -Werror in system/sepolicy

Bug: 66996870
Test: build with WITH_TIDY=1
Change-Id: I5df432c6d2f7ee19db89f44fbe3adec2bbcc0b41

tools/fc_sort/Android.mk

@@ -5,6 +5,7 @@ include $(CLEAR_VARS)
 LOCAL_MODULE := fc_sort
 LOCAL_MODULE_TAGS := optional
 LOCAL_SRC_FILES := fc_sort.c
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_CXX_STL := none
 
 include $(BUILD_HOST_EXECUTABLE)