Make build warnings be errors

Change-Id: Ia9e32a36f5c0268c8e85ebf25168821d8ad0162d
diff --git a/media/libnbaio/Android.mk b/media/libnbaio/Android.mk
index 16c5040..e2f416b 100644
--- a/media/libnbaio/Android.mk
+++ b/media/libnbaio/Android.mk
@@ -20,9 +20,6 @@
 #LOCAL_C_INCLUDES += path/to/libsndfile/src
 #LOCAL_STATIC_LIBRARIES += libsndfile
 
-# uncomment for systrace
-# LOCAL_CFLAGS += -DATRACE_TAG=ATRACE_TAG_AUDIO
-
 LOCAL_MODULE := libnbaio
 
 LOCAL_SHARED_LIBRARIES := \
@@ -34,4 +31,6 @@
 
 LOCAL_C_INCLUDES := $(call include-path-for, audio-utils)
 
+LOCAL_CFLAGS := -Werror -Wall
+
 include $(BUILD_SHARED_LIBRARY)