Fix uninitialized variable which could cause extra sleeps

Bug: 10569947
Change-Id: Id48d0a01d50fbfc8914c25756770be7a2a404b7c
diff --git a/audio/audio_hw.c b/audio/audio_hw.c
index d449030..81f1bf2 100644
--- a/audio/audio_hw.c
+++ b/audio/audio_hw.c
@@ -1130,7 +1130,7 @@
 static ssize_t out_write(struct audio_stream_out *stream, const void* buffer,
                          size_t bytes)
 {
-    int ret;
+    int ret = 0;
     struct stream_out *out = (struct stream_out *)stream;
     struct audio_device *adev = out->dev;
     int i;