FilterDirectoryReader.doClose() should call in.close() not in.doClose()

FilterDirectoryReader.doClose() calls in.doClose(). This is wrong because if you call close() on both the underlying reader and a wrapper around it, then doClose() will have been called several times, which will break ref counting.

Instead, FilterDirectoryReader.doClose() should call in.close() so that it is a no-op if the underlying reader is already closed, or so that calling close() on the underlying reader afterwards will be a no-op.