NdkMediaDataSource: fix getAvailableSize

Bug: 119127316
Test: NativeDecoderTest#testExtractorCachedDurationNative
Change-Id: I92b751f23d2598ea6c46ab79b80f9731f60b55e9
diff --git a/media/ndk/NdkMediaDataSourceCallbacks.cpp b/media/ndk/NdkMediaDataSourceCallbacks.cpp
index f40387f..86a57da 100644
--- a/media/ndk/NdkMediaDataSourceCallbacks.cpp
+++ b/media/ndk/NdkMediaDataSourceCallbacks.cpp
@@ -43,8 +43,8 @@
 ssize_t DataSource_getAvailableSize(void *userdata, off64_t offset) {
     off64_t size = -1;
     DataSource *source = static_cast<DataSource *>(userdata);
-    status_t err = source->getAvailableSize(offset, &size);
-    return  err == OK ? size : -1;
+    source->getAvailableSize(offset, &size);
+    return  size;
 }
 
 }  // namespace android