Merge pull request #4314 from TakuSemba/fix-bug-when-loading-init-data

close initDataSource after reading

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaChunk.java

@@ -237,7 +237,7 @@ import java.util.concurrent.atomic.AtomicInteger;
         initSegmentBytesLoaded = (int) (input.getPosition() - initDataSpec.absoluteStreamPosition);
       }
     } finally {
-      Util.closeQuietly(dataSource);
+      Util.closeQuietly(initDataSource);
     }
     initLoadCompleted = true;
   }