Reintroduce -Wall -Werror to check_seapp.

Also add attribute for a potential unused
function argument when dealing with darwin
SDK builds.

Change-Id: Iefdbecb050cc5fff6036f15413566e10cefa3813

tools/Android.mk

@@ -5,7 +5,7 @@ include $(CLEAR_VARS)
 LOCAL_MODULE := checkseapp
 LOCAL_MODULE_TAGS := optional
 LOCAL_C_INCLUDES := external/libsepol/include/
-LOCAL_CFLAGS := -DLINK_SEPOL_STATIC
+LOCAL_CFLAGS := -DLINK_SEPOL_STATIC -Wall -Werror
 LOCAL_SRC_FILES := check_seapp.c
 LOCAL_STATIC_LIBRARIES := libsepol
 

tools/check_seapp.c

@@ -436,7 +436,8 @@ static map_match rule_map_cmp(rule_map *rmA, rule_map *rmB) {
  * @param rm
  * 	rule map to be freed.
  */
-static void rule_map_free(rule_map *rm, rule_map_switch s) {
+static void rule_map_free(rule_map *rm,
+		rule_map_switch s __attribute__((unused)) /* only glibc builds, ignored otherwise */) {
 
 	size_t i;
 	size_t len = rm->length;