libcutils: turn on -Werror

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

Change-Id: I28c23fb213382a392ec30935749fb359e072d664
diff --git a/libcutils/Android.mk b/libcutils/Android.mk
index 635695a..405761c 100644
--- a/libcutils/Android.mk
+++ b/libcutils/Android.mk
@@ -77,7 +77,7 @@
 LOCAL_SRC_FILES := $(commonSources) $(commonHostSources) dlmalloc_stubs.c
 LOCAL_LDLIBS := -lpthread
 LOCAL_STATIC_LIBRARIES := liblog
-LOCAL_CFLAGS += $(hostSmpFlag)
+LOCAL_CFLAGS += $(hostSmpFlag) -Werror
 include $(BUILD_HOST_STATIC_LIBRARY)
 
 
@@ -88,14 +88,14 @@
 LOCAL_SRC_FILES := $(commonSources) $(commonHostSources) dlmalloc_stubs.c
 LOCAL_LDLIBS := -lpthread
 LOCAL_STATIC_LIBRARIES := lib64log
-LOCAL_CFLAGS += $(hostSmpFlag) -m64
+LOCAL_CFLAGS += $(hostSmpFlag) -m64 -Werror
 include $(BUILD_HOST_STATIC_LIBRARY)
 
 # Tests for host
 # ========================================================
 include $(CLEAR_VARS)
 LOCAL_MODULE := tst_str_parms
-LOCAL_CFLAGS += -DTEST_STR_PARMS
+LOCAL_CFLAGS += -DTEST_STR_PARMS -Werror
 LOCAL_SRC_FILES := str_parms.c hashmap.c memory.c
 LOCAL_STATIC_LIBRARIES := liblog
 LOCAL_MODULE_TAGS := optional
@@ -135,7 +135,7 @@
 
 LOCAL_C_INCLUDES := $(libcutils_c_includes)
 LOCAL_STATIC_LIBRARIES := liblog
-LOCAL_CFLAGS += $(targetSmpFlag)
+LOCAL_CFLAGS += $(targetSmpFlag) -Werror
 include $(BUILD_STATIC_LIBRARY)
 
 include $(CLEAR_VARS)
@@ -144,13 +144,13 @@
 # liblog symbols present in libcutils.
 LOCAL_WHOLE_STATIC_LIBRARIES := libcutils liblog
 LOCAL_SHARED_LIBRARIES := liblog
-LOCAL_CFLAGS += $(targetSmpFlag)
+LOCAL_CFLAGS += $(targetSmpFlag) -Werror
 LOCAL_C_INCLUDES := $(libcutils_c_includes)
 include $(BUILD_SHARED_LIBRARY)
 
 include $(CLEAR_VARS)
 LOCAL_MODULE := tst_str_parms
-LOCAL_CFLAGS += -DTEST_STR_PARMS
+LOCAL_CFLAGS += -DTEST_STR_PARMS -Werror
 LOCAL_SRC_FILES := str_parms.c hashmap.c memory.c
 LOCAL_SHARED_LIBRARIES := liblog
 LOCAL_MODULE_TAGS := optional