Remove png_read_end from SkPngScanlineDecoder

src/codec/SkCodec_libpng.h

Index: src/codec/SkCodec_libpng.h
diff --git a/src/codec/SkCodec_libpng.h b/src/codec/SkCodec_libpng.h
index cba5c2ad30e75b10ce5585146725b2f26ef794b5..f932a0a2ee6f30f259e76b3b1fb8f91c5918dd39 100644
--- a/src/codec/SkCodec_libpng.h
+++ b/src/codec/SkCodec_libpng.h
@@ -59,7 +59,6 @@ private:
     // Calls rewindIfNeeded and returns true if the decoder can continue.
     bool handleRewind();
     bool decodePalette(bool premultiply, int* ctableCount);
-    void finish();
     void destroyReadStruct();
 
     friend class SkPngScanlineDecoder;