Fix warnings for uninitialized local variables

Change-Id: Ic9b03b0fd215444e76c7b7bebb385f7831c557e0
diff --git a/media/libmedia/AudioTrack.cpp b/media/libmedia/AudioTrack.cpp
index 37fe182..ae81863 100644
--- a/media/libmedia/AudioTrack.cpp
+++ b/media/libmedia/AudioTrack.cpp
@@ -314,7 +314,7 @@
 void AudioTrack::start()
 {
     sp<AudioTrackThread> t = mAudioTrackThread;
-    status_t status;
+    status_t status = NO_ERROR;
 
     LOGV("start %p", this);
     if (t != 0) {
@@ -825,7 +825,7 @@
 {
     AutoMutex lock(mLock);
     int active;
-    status_t result;
+    status_t result = NO_ERROR;
     audio_track_cblk_t* cblk = mCblk;
     uint32_t framesReq = audioBuffer->frameCount;
     uint32_t waitTimeMs = (waitCount < 0) ? cblk->bufferTimeoutMs : WAIT_PERIOD_MS;