Enable strict warnings and fix unused warnings

Test: builds without warnings
Change-Id: I0701a44cbd9a2adc405a1e253b57df7ee03a90b7
diff --git a/media/libeffects/loudness/Android.mk b/media/libeffects/loudness/Android.mk
index 55d0611..3db4a79 100644
--- a/media/libeffects/loudness/Android.mk
+++ b/media/libeffects/loudness/Android.mk
@@ -8,6 +8,7 @@
 	dsp/core/dynamic_range_compression.cpp
 
 LOCAL_CFLAGS+= -O2 -fvisibility=hidden
+LOCAL_CFLAGS += -Wall -Werror
 
 LOCAL_SHARED_LIBRARIES := \
 	libcutils \
diff --git a/media/libeffects/loudness/EffectLoudnessEnhancer.cpp b/media/libeffects/loudness/EffectLoudnessEnhancer.cpp
index a5a1a3f..11c6133 100644
--- a/media/libeffects/loudness/EffectLoudnessEnhancer.cpp
+++ b/media/libeffects/loudness/EffectLoudnessEnhancer.cpp
@@ -194,7 +194,6 @@
                          effect_handle_t *pHandle) {
     ALOGV("LELib_Create()");
     int ret;
-    int i;
 
     if (pHandle == NULL || uuid == NULL) {
         return -EINVAL;
@@ -311,7 +310,6 @@
         void *pCmdData, uint32_t *replySize, void *pReplyData) {
 
     LoudnessEnhancerContext * pContext = (LoudnessEnhancerContext *)self;
-    int retsize;
 
     if (pContext == NULL || pContext->mState == LOUDNESS_ENHANCER_STATE_UNINITIALIZED) {
         return -EINVAL;