hal : Fix data initialization and input validation errors

 Initialize uninitialized variables and add null check to
 avoid following errors

 119251, 119255, 119256, 119257, 119258
 144012, 913366, 119249, 119250, 58938

Change-Id: I09d35977c9c3abf5819d5c72506c8d157158e212
diff --git a/post_proc/bundle.c b/post_proc/bundle.c
index 2bc7fad..d39a8b7 100644
--- a/post_proc/bundle.c
+++ b/post_proc/bundle.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2013-2016, The Linux Foundation. All rights reserved.
  * Not a Contribution.
  *
  * Copyright (C) 2013 The Android Open Source Project
@@ -287,7 +287,7 @@
 __attribute__ ((visibility ("default")))
 int offload_effects_bundle_hal_stop_output(audio_io_handle_t output, int pcm_id)
 {
-    int ret;
+    int ret = -1;
     struct listnode *node;
     struct listnode *fx_node;
     output_context_t *out_ctxt;