Use symbol AUDIO_IO_HANDLE_NONE from <system/audio.h>

Change-Id: Id6b1aa17558eb73e17f22b8eab6cd02e00a96dff
diff --git a/media/libmedia/AudioSystem.cpp b/media/libmedia/AudioSystem.cpp
index 8542404..301c7d6 100644
--- a/media/libmedia/AudioSystem.cpp
+++ b/media/libmedia/AudioSystem.cpp
@@ -196,12 +196,12 @@
 
 status_t AudioSystem::setParameters(const String8& keyValuePairs)
 {
-    return setParameters((audio_io_handle_t) 0, keyValuePairs);
+    return setParameters(AUDIO_IO_HANDLE_NONE, keyValuePairs);
 }
 
 String8 AudioSystem::getParameters(const String8& keys)
 {
-    return getParameters((audio_io_handle_t) 0, keys);
+    return getParameters(AUDIO_IO_HANDLE_NONE, keys);
 }
 
 // convert volume steps to natural log scale
@@ -284,7 +284,7 @@
     }
 
     output = getOutput(streamType);
-    if (output == 0) {
+    if (output == AUDIO_IO_HANDLE_NONE) {
         return PERMISSION_DENIED;
     }
 
@@ -329,7 +329,7 @@
     }
 
     output = getOutput(streamType);
-    if (output == 0) {
+    if (output == AUDIO_IO_HANDLE_NONE) {
         return PERMISSION_DENIED;
     }
 
@@ -413,7 +413,7 @@
     const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
     uint32_t result = 0;
     if (af == 0) return result;
-    if (ioHandle == 0) return result;
+    if (ioHandle == AUDIO_IO_HANDLE_NONE) return result;
 
     result = af->getInputFramesLost(ioHandle);
     return result;
@@ -464,7 +464,7 @@
     const OutputDescriptor *desc;
     audio_stream_type_t stream;
 
-    if (ioHandle == 0) return;
+    if (ioHandle == AUDIO_IO_HANDLE_NONE) return;
 
     Mutex::Autolock _l(AudioSystem::gLock);
 
@@ -738,7 +738,7 @@
 {
     const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
     // FIXME change return type to status_t, and return PERMISSION_DENIED here
-    if (aps == 0) return 0;
+    if (aps == 0) return AUDIO_IO_HANDLE_NONE;
     return aps->getOutputForEffect(desc);
 }